Home Heating... Wood Combustion vs Home Solar?

I did a thought experiment and asked ChatGPT to crunch the numbers of a series of questions related to the costs of making and running a wood stove, versus setting up a home solar energy system just for home heating.

The basic parameters are for 10kW of heat output for 4 hours per day, 6 months per year. I have made some basic assumptions and granted the Solar option the huge discount of not needed maintenance or upgrades for 20 years, whereas we replaced the wood heater at 10 years.

This is not meant to be exhaustive nor definitive, rather a suggestive comparison on the 3 metrics of financial, carbon and energy cost. I will bold my questions and the rest is AI generated. I have not verified the data, but on casual glance it appears reasonable.

Take this as a thought experiment and if you can think of ways to improve the questions and/or the results, please let me know.

TL:DR;

Here’s the comparison chart illustrating the Financial, Energy, and Carbon Costs for the two systems:

Wood Stove

Financial Cost: $38,250
Energy Cost: 205 kWh
Carbon Cost: 68 kg CO2

Solar System

Financial Cost: $81,100
Energy Cost: 39,200 kWh
Carbon Cost: 42,500 kg CO2

what would be the carbon cost of making a 50kg stove, including all aspects from mining to steel production to manufacturing to distribution. Assume the steel production and manufacture occur in India, and the plants are no more than 1000kms apart and the end user is not more than 1000kms from the manufacturing plant

ChatGPT

To estimate the carbon cost of making a 50kg stove, we need to consider several stages: mining and raw material extraction, steel production, manufacturing, and distribution. Here’s a step-by-step breakdown:

1. Mining and Raw Material Extraction

Iron Ore Extraction: Approximately 1.6 tonnes of iron ore are needed to produce 1 tonne of steel.
Carbon Cost of Mining: The carbon footprint of mining iron ore is about 0.1-0.2 tonnes of CO2 per tonne of ore extracted.

For 50 kg of steel: 50 kg×1.6×0.15 (average CO2/tonne of ore)=12 kg CO250 \text{ kg} \times 1.6 \times 0.15 \text{ (average CO2/tonne of ore)} = 12 \text{ kg CO2}50 kg×1.6×0.15 (average CO2/tonne of ore)=12 kg CO2

2. Steel Production

Blast Furnace/Basic Oxygen Furnace (BF/BOF) Method: Typically, the carbon footprint is about 2.0 tonnes of CO2 per tonne of steel produced.
Electric Arc Furnace (EAF) Method: Typically, the carbon footprint is about 0.4 tonnes of CO2 per tonne of steel produced.

Assuming the more common BF/BOF method: 50 kg×2.0 (CO2/tonne of steel)=100 kg CO250 \text{ kg} \times 2.0 \text{ (CO2/tonne of steel)} = 100 \text{ kg CO2}50 kg×2.0 (CO2/tonne of steel)=100 kg CO2

3. Manufacturing Process

Fabrication and Assembly: This varies widely, but a rough estimate can be around 0.1 tonnes of CO2 per tonne of product.

For 50 kg of manufactured stove: 50 kg×0.1 (CO2/tonne of product)=5 kg CO250 \text{ kg} \times 0.1 \text{ (CO2/tonne of product)} = 5 \text{ kg CO2}50 kg×0.1 (CO2/tonne of product)=5 kg CO2

4. Distribution

Transportation Emissions: Assuming transportation is done via trucks, the average carbon footprint is about 0.1 kg CO2 per tonne-kilometer.
From Steel Plant to Manufacturing Plant: 50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO250 \text{ kg} \times 1000 \text{ km} \times 0.1 \text{ (CO2/tonne-km)} = 5 \text{ kg CO2}50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO2
From Manufacturing Plant to End User: 50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO250 \text{ kg} \times 1000 \text{ km} \times 0.1 \text{ (CO2/tonne-km)} = 5 \text{ kg CO2}50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO2

Total Carbon Footprint

Summing up all the stages:

Mining: 12 kg CO2
Steel Production: 100 kg CO2
Manufacturing: 5 kg CO2
Distribution (Steel Plant to Manufacturing): 5 kg CO2
Distribution (Manufacturing to End User): 5 kg CO2

Total Carbon Cost=12+100+5+5+5=127 kg CO2\text{Total Carbon Cost} = 12 + 100 + 5 + 5 + 5 = 127 \text{ kg CO2}Total Carbon Cost=12+100+5+5+5=127 kg CO2

Therefore, the estimated carbon cost of making a 50kg stove, considering all stages from mining to distribution, is approximately 127 kg CO2.

Ok, now let’s say the iron ore is mined in Australia, and the end user is in Australia, and the steel production and manufacturing is in India

ChatGPT

Let’s update the carbon footprint estimation considering the iron ore is mined in Australia, the steel production and manufacturing are in India, and the end user is in Australia. Here’s the revised step-by-step breakdown:

1. Mining and Raw Material Extraction (Australia)

Iron Ore Extraction: The carbon cost remains the same as before.

2. Transportation of Iron Ore (Australia to India)

Shipping Emissions: The carbon footprint for shipping is approximately 0.01 kg CO2 per tonne-kilometer.
Distance (approximate): 10,000 km.

50 kg×10,000 km×0.01 (CO2/tonne-km)=5 kg CO250 \text{ kg} \times 10,000 \text{ km} \times 0.01 \text{ (CO2/tonne-km)} = 5 \text{ kg CO2}50 kg×10,000 km×0.01 (CO2/tonne-km)=5 kg CO2

3. Steel Production (India)

Steel Production Using BF/BOF Method:

50 kg×2.0 (CO2/tonne of steel)=100 kg CO250 \text{ kg} \times 2.0 \text{ (CO2/tonne of steel)} = 100 \text{ kg CO2}50 kg×2.0 (CO2/tonne of steel)=100 kg CO2

4. Manufacturing Process (India)

Fabrication and Assembly:

50 kg×0.1 (CO2/tonne of product)=5 kg CO250 \text{ kg} \times 0.1 \text{ (CO2/tonne of product)} = 5 \text{ kg CO2}50 kg×0.1 (CO2/tonne of product)=5 kg CO2

5. Transportation of Finished Stove (India to Australia)

Shipping Emissions: Similar to the iron ore transportation.
Distance (approximate): 10,000 km.

50 kg×10,000 km×0.01 (CO2/tonne-km)=5 kg CO250 \text{ kg} \times 10,000 \text{ km} \times 0.01 \text{ (CO2/tonne-km)} = 5 \text{ kg CO2}50 kg×10,000 km×0.01 (CO2/tonne-km)=5 kg CO2

6. Distribution within Australia

Transportation Emissions: Assuming transportation is done via trucks, the average carbon footprint is about 0.1 kg CO2 per tonne-kilometer.
From Australian Port to End User: 50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO250 \text{ kg} \times 1000 \text{ km} \times 0.1 \text{ (CO2/tonne-km)} = 5 \text{ kg CO2}50 kg×1000 km×0.1 (CO2/tonne-km)=5 kg CO2

Total Carbon Footprint

Summing up all the stages:

Mining: 12 kg CO2
Transportation of Iron Ore: 5 kg CO2
Steel Production: 100 kg CO2
Manufacturing: 5 kg CO2
Transportation of Finished Stove: 5 kg CO2
Distribution within Australia: 5 kg CO2

Total Carbon Cost=12+5+100+5+5+5=132 kg CO2\text{Total Carbon Cost} = 12 + 5 + 100 + 5 + 5 + 5 = 132 \text{ kg CO2}Total Carbon Cost=12+5+100+5+5+5=132 kg CO2

Therefore, the estimated carbon cost of making a 50kg stove, considering iron ore mining in Australia, steel production and manufacturing in India, and the end user in Australia, is approximately 132 kg CO2.

If you adjust this for a 25kg stove, is the end result half?

ChatGPT

Let’s adjust the calculation for a 25kg stove. Generally, for linear processes like these, halving the weight should approximately halve the emissions. However, let’s go through each stage to confirm.

1. Mining and Raw Material Extraction (Australia)

Iron Ore Extraction: 25 kg×1.6×0.15 (average CO2/tonne of ore)=6 kg CO225 \text{ kg} \times 1.6 \times 0.15 \text{ (average CO2/tonne of ore)} = 6 \text{ kg CO2}25 kg×1.6×0.15 (average CO2/tonne of ore)=6 kg CO2

2. Transportation of Iron Ore (Australia to India)

Shipping Emissions: 25 kg×10,000 km×0.01 (CO2/tonne-km)=2.5 kg CO225 \text{ kg} \times 10,000 \text{ km} \times 0.01 \text{ (CO2/tonne-km)} = 2.5 \text{ kg CO2}25 kg×10,000 km×0.01 (CO2/tonne-km)=2.5 kg CO2

3. Steel Production (India)

Steel Production Using BF/BOF Method: 25 kg×2.0 (CO2/tonne of steel)=50 kg CO225 \text{ kg} \times 2.0 \text{ (CO2/tonne of steel)} = 50 \text{ kg CO2}25 kg×2.0 (CO2/tonne of steel)=50 kg CO2

4. Manufacturing Process (India)

Fabrication and Assembly: 25 kg×0.1 (CO2/tonne of product)=2.5 kg CO225 \text{ kg} \times 0.1 \text{ (CO2/tonne of product)} = 2.5 \text{ kg CO2}25 kg×0.1 (CO2/tonne of product)=2.5 kg CO2

5. Transportation of Finished Stove (India to Australia)

Shipping Emissions: 25 kg×10,000 km×0.01 (CO2/tonne-km)=2.5 kg CO225 \text{ kg} \times 10,000 \text{ km} \times 0.01 \text{ (CO2/tonne-km)} = 2.5 \text{ kg CO2}25 kg×10,000 km×0.01 (CO2/tonne-km)=2.5 kg CO2

6. Distribution within Australia

Transportation Emissions: 25 kg×1000 km×0.1 (CO2/tonne-km)=2.5 kg CO225 \text{ kg} \times 1000 \text{ km} \times 0.1 \text{ (CO2/tonne-km)} = 2.5 \text{ kg CO2}25 kg×1000 km×0.1 (CO2/tonne-km)=2.5 kg CO2

Total Carbon Footprint

Summing up all the stages:

Mining: 6 kg CO2
Transportation of Iron Ore: 2.5 kg CO2
Steel Production: 50 kg CO2
Manufacturing: 2.5 kg CO2
Transportation of Finished Stove: 2.5 kg CO2
Distribution within Australia: 2.5 kg CO2

Total Carbon Cost=6+2.5+50+2.5+2.5+2.5=68 kg CO2\text{Total Carbon Cost} = 6 + 2.5 + 50 + 2.5 + 2.5 + 2.5 = 68 \text{ kg CO2}Total Carbon Cost=6+2.5+50+2.5+2.5+2.5=68 kg CO2

Therefore, the estimated carbon cost of making a 25kg stove, considering the same conditions, is approximately 68 kg CO2. This is about half of the carbon cost for a 50kg stove, confirming the linear relationship in this context.

What are the other ecological costs related to making a steel product of this weight?

ChatGPT

In addition to the carbon footprint, there are several other ecological costs associated with making a steel product. Here are the key considerations:

1. Resource Depletion

Iron Ore: The extraction of iron ore depletes finite natural resources, affecting the availability of these materials for future generations.
Energy Resources: Significant amounts of fossil fuels are consumed in mining, transportation, and steel production processes.

2. Land Use and Habitat Destruction

Mining Operations: Mining activities can lead to deforestation, soil erosion, and the destruction of habitats for many species. It can also cause significant changes to local landscapes and ecosystems.
Industrial Sites: The establishment and operation of steel plants and manufacturing facilities require substantial land, often leading to the displacement of wildlife and alteration of natural landscapes.

3. Water Use and Pollution

Water Consumption: Steel production is water-intensive. Water is used for cooling, dust control, and in various chemical processes.
Water Pollution: The discharge of pollutants into water bodies, including heavy metals, particulates, and chemicals used in processing, can harm aquatic ecosystems and contaminate drinking water sources.

4. Air Pollution

Particulate Matter: The steel industry releases particulate matter (PM), which can cause respiratory problems in humans and animals.
Other Emissions: Besides CO2, steel production emits sulfur dioxide (SO2) and nitrogen oxides (NOx), which contribute to acid rain and smog, affecting air quality and human health.

5. Soil Contamination

Waste Products: Slag, a by-product of steel production, can contain harmful substances like heavy metals that, if not properly managed, can leach into the soil and groundwater, causing long-term contamination.

6. Biodiversity Loss

Habitat Destruction: Mining and industrial activities often lead to the loss of biodiversity as species are displaced or destroyed. This can lead to a decline in ecosystem health and the loss of ecosystem services.

7. Energy Consumption

Non-Renewable Energy: The energy used in steel production largely comes from non-renewable sources such as coal, which contributes to environmental degradation and greenhouse gas emissions.

8. Waste Generation

Solid Waste: The production process generates substantial amounts of solid waste, including slag, sludge, and dust, which need to be managed and disposed of properly.
Hazardous Waste: Certain processes in steel production can generate hazardous waste that requires careful handling and disposal to prevent environmental contamination.

9. Transportation Impact

Fuel Consumption: The transportation of raw materials and finished products consumes fossil fuels, contributing to air pollution and greenhouse gas emissions.
Infrastructure Wear: Heavy transportation can lead to increased wear and tear on infrastructure, leading to environmental and economic costs associated with repairs and maintenance.

10. Noise Pollution

Industrial Noise: Mining, steel production, and manufacturing processes generate significant noise, which can disturb both human and wildlife populations.

Addressing these ecological costs requires a comprehensive approach that includes more efficient resource use, cleaner production technologies, better waste management practices, and policies aimed at reducing the overall environmental impact of steel production.

What would be the energy footprint for this stove, in kW?

ChatGPT

To estimate the energy footprint for producing a 25kg steel stove, we’ll need to consider the energy consumed at each stage of the production process: mining and raw material extraction, steel production, manufacturing, and transportation. Here’s a detailed breakdown:

1. Mining and Raw Material Extraction

Energy Consumption for Iron Ore Mining: The average energy consumption is approximately 500 kWh per tonne of iron ore extracted.

For 25 kg of steel: 25 kg×1.6 (ore/steel ratio)×500 kWh1000 kg=20 kWh25 \text{ kg} \times 1.6 \text{ (ore/steel ratio)} \times \frac{500 \text{ kWh}}{1000 \text{ kg}} = 20 \text{ kWh}25 kg×1.6 (ore/steel ratio)×1000 kg500 kWh=20 kWh

2. Steel Production

Energy Consumption for BF/BOF Method: The average energy consumption is about 18 GJ (gigajoules) per tonne of steel.
Conversion: 1 GJ = 277.78 kWh

For 25 kg of steel: 25 kg×18 GJ/tonne×277.78 kWh1000 kg=125 kWh25 \text{ kg} \times 18 \text{ GJ/tonne} \times \frac{277.78 \text{ kWh}}{1000 \text{ kg}} = 125 \text{ kWh}25 kg×18 GJ/tonne×1000 kg277.78 kWh=125 kWh

3. Manufacturing Process

Energy Consumption for Fabrication and Assembly: This can vary, but an average estimate is 100 kWh per tonne of product.

For 25 kg of manufactured stove: 25 kg×100 kWh1000 kg=2.5 kWh25 \text{ kg} \times \frac{100 \text{ kWh}}{1000 \text{ kg}} = 2.5 \text{ kWh}25 kg×1000 kg100 kWh=2.5 kWh

4. Transportation

Energy Consumption for Shipping (Australia to India): Energy consumption for shipping is approximately 0.1 kWh per tonne-kilometer.
Distance: Approximately 10,000 km.

For 25 kg of iron ore: 25 kg×10,000 km×0.1 kWh1000 kg-km=25 kWh25 \text{ kg} \times 10,000 \text{ km} \times \frac{0.1 \text{ kWh}}{1000 \text{ kg-km}} = 25 \text{ kWh}25 kg×10,000 km×1000 kg-km0.1 kWh=25 kWh

Energy Consumption for Shipping (India to Australia): Similar to iron ore shipping.
Distance: Approximately 10,000 km.

For 25 kg of finished stove: 25 kg×10,000 km×0.1 kWh1000 kg-km=25 kWh25 \text{ kg} \times 10,000 \text{ km} \times \frac{0.1 \text{ kWh}}{1000 \text{ kg-km}} = 25 \text{ kWh}25 kg×10,000 km×1000 kg-km0.1 kWh=25 kWh

Energy Consumption for Truck Transportation within Australia: Average energy consumption is 0.3 kWh per tonne-kilometer.
Distance: 1000 km.

For 25 kg of finished stove: 25 kg×1000 km×0.3 kWh1000 kg-km=7.5 kWh25 \text{ kg} \times 1000 \text{ km} \times \frac{0.3 \text{ kWh}}{1000 \text{ kg-km}} = 7.5 \text{ kWh}25 kg×1000 km×1000 kg-km0.3 kWh=7.5 kWh

Total Energy Footprint

Summing up all the stages:

Mining: 20 kWh
Steel Production: 125 kWh
Manufacturing: 2.5 kWh
Shipping (Australia to India): 25 kWh
Shipping (India to Australia): 25 kWh
Truck Transportation within Australia: 7.5 kWh

Total Energy Footprint=20+125+2.5+25+25+7.5=205 kWh\text{Total Energy Footprint} = 20 + 125 + 2.5 + 25 + 25 + 7.5 = 205 \text{ kWh}Total Energy Footprint=20+125+2.5+25+25+7.5=205 kWh

Therefore, the estimated energy footprint for producing a 25kg steel stove, considering all stages from mining to distribution, is approximately 205 kWh.

And let’s assume that this stove converts wood to thermal energy with an output of 10kW, and let’s say it consumes 2.5 kg per hour to do so, what’s the energy conversion rate, or the efficiency?

ChatGPT

To determine the energy conversion efficiency of the stove, we’ll compare the thermal energy output to the energy content of the wood consumed. Here’s the step-by-step calculation:

1. Thermal Energy Output

The stove produces 10 kW of thermal energy.

2. Wood Consumption

The stove consumes 2.5 kg of wood per hour.

3. Energy Content of Wood

The energy content of wood varies, but a typical value is about 15-20 MJ/kg.
Let’s use an average value of 17.5 MJ/kg for this calculation.

4. Energy Content of Wood Consumed per Hour

Energy content per hour=2.5 kg/hour×17.5 MJ/kg\text{Energy content per hour} = 2.5 \text{ kg/hour} \times 17.5 \text{ MJ/kg}Energy content per hour=2.5 kg/hour×17.5 MJ/kg Energy content per hour=43.75 MJ/hour\text{Energy content per hour} = 43.75 \text{ MJ/hour}Energy content per hour=43.75 MJ/hour

5. Converting MJ to kWh

1 MJ = 0.27778 kWh

43.75 MJ/hour×0.27778 kWh/MJ=12.15 kWh/hour43.75 \text{ MJ/hour} \times 0.27778 \text{ kWh/MJ} = 12.15 \text{ kWh/hour}43.75 MJ/hour×0.27778 kWh/MJ=12.15 kWh/hour

6. Efficiency Calculation

Efficiency (η\etaη) is calculated as the ratio of the useful thermal energy output to the energy input from the wood.

η=Thermal Energy OutputEnergy Input\eta = \frac{\text{Thermal Energy Output}}{\text{Energy Input}}η=Energy InputThermal Energy Output η=10 kW12.15 kWh/hour\eta = \frac{10 \text{ kW}}{12.15 \text{ kWh/hour}}η=12.15 kWh/hour10 kW \eta \approx 0.823 \text{ (or 82.3%)}

Conclusion

The energy conversion efficiency of the stove is approximately 82.3%. This means that 82.3% of the energy content in the wood is converted into useful thermal energy.

that seems like a very good figure… what would be a typical conversion efficiency for a wood combustion heater?

ChatGPT

The conversion efficiency of a wood combustion heater can vary widely based on the design, technology, and operating conditions. Here are some typical efficiency ranges for different types of wood stoves and heaters:

1. Traditional Open Fireplaces

Efficiency: 10-20%
Notes: Most of the heat escapes through the chimney, and they are not designed for efficient combustion.

2. Conventional Wood Stoves

Efficiency: 40-60%
Notes: Older models and simpler designs without advanced technology for improving combustion and heat retention.

3. Modern EPA-Certified Wood Stoves

Efficiency: 60-80%
Notes: These stoves are designed to meet strict emissions standards and often incorporate features like secondary combustion, catalytic converters, and improved insulation.

4. Pellet Stoves

Efficiency: 70-90%
Notes: These stoves use compressed wood pellets and have controlled combustion processes, leading to higher efficiency.

5. High-Efficiency Wood Boilers and Furnaces

Efficiency: 80-90%
Notes: These systems are designed for heating larger spaces and often incorporate advanced combustion technologies and heat exchangers.

Summary

An efficiency of 82.3% for a wood combustion heater, as calculated for your stove, is indeed on the higher end of the spectrum. This suggests that the stove is designed with advanced combustion technologies that maximize the conversion of wood energy into usable heat while minimizing losses.

It’s important to note that actual efficiency can be influenced by several factors, including:

Quality of the Wood: Properly seasoned, dry wood burns more efficiently than green or wet wood.
Maintenance: Regular cleaning and maintenance of the stove and chimney can prevent blockages and improve efficiency.
Operating Conditions: Proper air supply and combustion temperature can significantly impact the stove’s performance.
Design Features: Innovations like secondary combustion, insulation, and catalytic converters enhance efficiency.

Overall, an 82.3% efficiency indicates a highly efficient wood stove, comparable to the best available models on the market today.

Ok so let’s say this unit is used on average for 4 hours per day for half the year, what is the total energy output

ChatGPT

To calculate the total energy output, we need to determine the number of hours the stove is used per year and then multiply that by the thermal energy output per hour. Here’s the step-by-step calculation:

1. Daily Usage

Hours per day: 4 hours

2. Annual Usage

Days per year: Half the year (365 / 2) = 182.5 days

3. Total Hours per Year

Total hours per year=4 hours/day×182.5 days/year=730 hours/year\text{Total hours per year} = 4 \text{ hours/day} \times 182.5 \text{ days/year} = 730 \text{ hours/year}Total hours per year=4 hours/day×182.5 days/year=730 hours/year

4. Energy Output per Hour

Thermal energy output: 10 kW

5. Total Energy Output per Year

Total energy output=10 kW×730 hours/year=7300 kWh/year\text{Total energy output} = 10 \text{ kW} \times 730 \text{ hours/year} = 7300 \text{ kWh/year}Total energy output=10 kW×730 hours/year=7300 kWh/year

Conclusion

The total energy output of the stove, when used on average for 4 hours per day for half the year, is 7300 kWh per year.

And let’s say we were going to replace this heater with solar power and batteries and inverter and heaters… what would be the required size of these components

ChatGPT

To replace the wood heater with a solar power system including solar panels, batteries, an inverter, and electric heaters, we need to determine the size and capacity of each component based on the energy needs. Here’s a detailed breakdown:

1. Total Energy Requirement

From the previous calculation, the total energy output needed per year is 7300 kWh.

2. Daily Energy Requirement

Daily energy requirement=7300 kWh/year182.5 days/year≈40 kWh/day\text{Daily energy requirement} = \frac{7300 \text{ kWh/year}}{182.5 \text{ days/year}} \approx 40 \text{ kWh/day}Daily energy requirement=182.5 days/year7300 kWh/year≈40 kWh/day

3. Solar Panel System Size

Average Solar Irradiance: This varies by location, but a common average is about 4-5 peak sun hours per day.
Daily Energy Production Needed: 40 kWh/day

Required solar panel capacity=40 kWh/day4.5 peak sun hours/day≈8.89 kW\text{Required solar panel capacity} = \frac{40 \text{ kWh/day}}{4.5 \text{ peak sun hours/day}} \approx 8.89 \text{ kW}Required solar panel capacity=4.5 peak sun hours/day40 kWh/day≈8.89 kW

Rounding up for efficiency losses and to ensure consistent energy supply: Solar panel system size≈9−10 kW\text{Solar panel system size} \approx 9-10 \text{ kW}Solar panel system size≈9−10 kW

4. Battery Storage

Daily Energy Requirement: 40 kWh
Days of Autonomy: Typically, 2-3 days of autonomy is recommended to account for cloudy days and ensure a consistent power supply.

Battery storage capacity=40 kWh/day×3 days=120 kWh\text{Battery storage capacity} = 40 \text{ kWh/day} \times 3 \text{ days} = 120 \text{ kWh}Battery storage capacity=40 kWh/day×3 days=120 kWh

5. Inverter Size

Peak Power Demand: Assuming electric heaters and other appliances run simultaneously, the inverter needs to handle the peak power load. Electric heaters typically have a high power draw.

Assuming the heaters need to produce 10 kW of thermal energy, and allowing for other household usage: Inverter size≈12−15 kW\text{Inverter size} \approx 12-15 \text{ kW}Inverter size≈12−15 kW

Component Summary

Solar Panels: 9-10 kW system
Battery Storage: 120 kWh capacity
Inverter: 12-15 kW capacity

Additional Considerations

Energy Efficiency: Installing energy-efficient electric heaters can reduce the overall energy requirement.
Backup Power: Including a backup generator or additional solar capacity to handle periods of low sunlight can improve reliability.
Grid-Tied vs. Off-Grid: If the system is grid-tied, the battery storage requirements can be reduced as the grid can act as a backup.

Conclusion

To replace the wood heater with a solar power system, you would need approximately:

A 9-10 kW solar panel array
120 kWh of battery storage
A 12-15 kW inverter

This setup would ensure you have sufficient power to meet your heating needs along with other household electricity requirements.

any idea of the approx cost for this setup?

ChatGPT

The cost of a solar power system with batteries, an inverter, and electric heaters can vary widely based on location, quality of components, and installation costs. However, I can provide a rough estimate based on average costs in many markets.

1. Solar Panels

Cost per Watt: Around $2.50 to $3.50 per watt installed.
Total System Size: 9-10 kW.

For a 9-10 kW system: Cost=9,000 W×$2.50 to $3.50 per W\text{Cost} = 9,000 \text{ W} \times \$2.50 \text{ to } \$3.50 \text{ per W}Cost=9,000 W×$2.50 to $3.50 per W Cost=$22,500 to $31,500\text{Cost} = \$22,500 \text{ to } \$31,500Cost=$22,500 to $31,500

2. Battery Storage

Cost per kWh: Around $400 to $600 per kWh installed.
Total Storage Capacity: 120 kWh.

For 120 kWh of storage: Cost=120 kWh×$400 to $600 per kWh\text{Cost} = 120 \text{ kWh} \times \$400 \text{ to } \$600 \text{ per kWh}Cost=120 kWh×$400 to $600 per kWh Cost=$48,000 to $72,000\text{Cost} = \$48,000 \text{ to } \$72,000Cost=$48,000 to $72,000

3. Inverter

Cost per kW: Around $800 to $1,200 per kW installed.
Total Inverter Size: 12-15 kW.

For a 12-15 kW inverter: Cost=12,000 to 15,000 W×$800 to $1,200 per kW\text{Cost} = 12,000 \text{ to } 15,000 \text{ W} \times \$800 \text{ to } \$1,200 \text{ per kW}Cost=12,000 to 15,000 W×$800 to $1,200 per kW Cost=$9,600 to $18,000\text{Cost} = \$9,600 \text{ to } \$18,000Cost=$9,600 to $18,000

4. Electric Heaters

Cost per Unit: Around $500 to $1,500 per unit installed.
Number of Units: Assuming 2-3 heaters to meet the heating requirement.

For 2-3 electric heaters: Cost=2 to 3×$500 to $1,500\text{Cost} = 2 \text{ to } 3 \times \$500 \text{ to } \$1,500Cost=2 to 3×$500 to $1,500 Cost=$1,000 to $4,500\text{Cost} = \$1,000 \text{ to } \$4,500Cost=$1,000 to $4,500

Total Estimated Cost

Summing up the costs for all components: Solar Panels=$22,500 to $31,500\text{Solar Panels} = \$22,500 \text{ to } \$31,500Solar Panels=$22,500 to $31,500 Battery Storage=$48,000 to $72,000\text{Battery Storage} = \$48,000 \text{ to } \$72,000Battery Storage=$48,000 to $72,000 Inverter=$9,600 to $18,000\text{Inverter} = \$9,600 \text{ to } \$18,000Inverter=$9,600 to $18,000 Electric Heaters=$1,000 to $4,500\text{Electric Heaters} = \$1,000 \text{ to } \$4,500Electric Heaters=$1,000 to $4,500

Total Cost=($22,500+$48,000+$9,600+$1,000) to ($31,500+$72,000+$18,000+$4,500)\text{Total Cost} = (\$22,500 + \$48,000 + \$9,600 + \$1,000) \text{ to } (\$31,500 + \$72,000 + \$18,000 + \$4,500)Total Cost=($22,500+$48,000+$9,600+$1,000) to ($31,500+$72,000+$18,000+$4,500) Total Cost=$81,100 to $126,000\text{Total Cost} = \$81,100 \text{ to } \$126,000Total Cost=$81,100 to $126,000

Conclusion

The approximate cost for setting up a solar power system to replace a wood heater, including solar panels, batteries, an inverter, and electric heaters, would be between $81,100 and $126,000. This estimate includes installation and component costs but can vary based on specific market conditions and installation complexities.

what would be the carbon cost to make all these components?

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Estimating the carbon cost to manufacture all the components of a solar power system involves considering the production and transportation emissions for solar panels, batteries, inverters, and electric heaters. Here’s a detailed breakdown:

1. Solar Panels

The carbon footprint of producing solar panels is generally estimated to be between 20-40 grams of CO2 per kWh of energy generated over their lifetime. For manufacturing purposes, let’s use a more direct estimate:

Production Carbon Footprint: Approximately 1,500 kg CO2 per kW of solar panels.

For a 9-10 kW system: 9 kW×1,500 kg CO2/kW=13,500 kg CO29 \text{ kW} \times 1,500 \text{ kg CO2/kW} = 13,500 \text{ kg CO2}9 kW×1,500 kg CO2/kW=13,500 kg CO2 10 kW×1,500 kg CO2/kW=15,000 kg CO210 \text{ kW} \times 1,500 \text{ kg CO2/kW} = 15,000 \text{ kg CO2}10 kW×1,500 kg CO2/kW=15,000 kg CO2

2. Battery Storage

Lithium-ion batteries have a carbon footprint of approximately 150-200 kg CO2 per kWh of storage capacity.

Production Carbon Footprint: 150-200 kg CO2 per kWh.

For 120 kWh of battery storage: 120 kWh×150 kg CO2/kWh=18,000 kg CO2120 \text{ kWh} \times 150 \text{ kg CO2/kWh} = 18,000 \text{ kg CO2}120 kWh×150 kg CO2/kWh=18,000 kg CO2 120 kWh×200 kg CO2/kWh=24,000 kg CO2120 \text{ kWh} \times 200 \text{ kg CO2/kWh} = 24,000 \text{ kg CO2}120 kWh×200 kg CO2/kWh=24,000 kg CO2

3. Inverter

The carbon footprint of manufacturing inverters is approximately 500 kg CO2 per kW.

Production Carbon Footprint: 500 kg CO2 per kW.

For a 12-15 kW inverter: 12 kW×500 kg CO2/kW=6,000 kg CO212 \text{ kW} \times 500 \text{ kg CO2/kW} = 6,000 \text{ kg CO2}12 kW×500 kg CO2/kW=6,000 kg CO2 15 kW×500 kg CO2/kW=7,500 kg CO215 \text{ kW} \times 500 \text{ kg CO2/kW} = 7,500 \text{ kg CO2}15 kW×500 kg CO2/kW=7,500 kg CO2

4. Electric Heaters

The carbon footprint for manufacturing electric heaters is approximately 200 kg CO2 per unit.

Production Carbon Footprint: 200 kg CO2 per unit.

For 2-3 electric heaters: 2 units×200 kg CO2/unit=400 kg CO22 \text{ units} \times 200 \text{ kg CO2/unit} = 400 \text{ kg CO2}2 units×200 kg CO2/unit=400 kg CO2 3 units×200 kg CO2/unit=600 kg CO23 \text{ units} \times 200 \text{ kg CO2/unit} = 600 \text{ kg CO2}3 units×200 kg CO2/unit=600 kg CO2

Total Carbon Footprint

Summing up the carbon footprints for all components:

Solar Panels: 13,500 to 15,000 kg CO2
Battery Storage: 18,000 to 24,000 kg CO2
Inverter: 6,000 to 7,500 kg CO2
Electric Heaters: 400 to 600 kg CO2

Total Carbon Footprint=(13,500+18,000+6,000+400) to (15,000+24,000+7,500+600)\text{Total Carbon Footprint} = (13,500 + 18,000 + 6,000 + 400) \text{ to } (15,000 + 24,000 + 7,500 + 600)Total Carbon Footprint=(13,500+18,000+6,000+400) to (15,000+24,000+7,500+600) Total Carbon Footprint=37,900 to 47,100 kg CO2\text{Total Carbon Footprint} = 37,900 \text{ to } 47,100 \text{ kg CO2}Total Carbon Footprint=37,900 to 47,100 kg CO2

Conclusion

The estimated carbon cost to manufacture all the components of a solar power system (including solar panels, batteries, an inverter, and electric heaters) to replace a wood heater is approximately 37,900 to 47,100 kg CO2. This range accounts for variations in the carbon footprints of different components and their capacities.

and what is the energy cost to make all these components and get them onsite?

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To estimate the energy cost to manufacture all the components of a solar power system and get them onsite, we need to consider the energy required for production and transportation for each component. Here’s a detailed breakdown:

1. Solar Panels

The energy payback time (EPBT) for solar panels is typically 1-3 years, meaning the energy required to produce the panels is equivalent to 1-3 years of their energy output.

Production Energy Cost: Approximately 2,500 kWh per kW of solar panels.

For a 9-10 kW system: 9 kW×2,500 kWh/kW=22,500 kWh9 \text{ kW} \times 2,500 \text{ kWh/kW} = 22,500 \text{ kWh}9 kW×2,500 kWh/kW=22,500 kWh 10 kW×2,500 kWh/kW=25,000 kWh10 \text{ kW} \times 2,500 \text{ kWh/kW} = 25,000 \text{ kWh}10 kW×2,500 kWh/kW=25,000 kWh

2. Battery Storage

The energy cost to produce lithium-ion batteries is estimated to be around 1.5-2.5 kWh per kWh of battery capacity.

Production Energy Cost: 1.5-2.5 kWh per kWh.

For 120 kWh of battery storage: 120 kWh×1.5 kWh/kWh=180 kWh120 \text{ kWh} \times 1.5 \text{ kWh/kWh} = 180 \text{ kWh}120 kWh×1.5 kWh/kWh=180 kWh 120 kWh×2.5 kWh/kWh=300 kWh120 \text{ kWh} \times 2.5 \text{ kWh/kWh} = 300 \text{ kWh}120 kWh×2.5 kWh/kWh=300 kWh

3. Inverter

The energy cost to produce inverters is around 1,000-1,500 kWh per kW.

Production Energy Cost: 1,000-1,500 kWh per kW.

For a 12-15 kW inverter: 12 kW×1,000 kWh/kW=12,000 kWh12 \text{ kW} \times 1,000 \text{ kWh/kW} = 12,000 \text{ kWh}12 kW×1,000 kWh/kW=12,000 kWh 15 kW×1,000 kWh/kW=15,000 kWh15 \text{ kW} \times 1,000 \text{ kWh/kW} = 15,000 \text{ kWh}15 kW×1,000 kWh/kW=15,000 kWh

4. Electric Heaters

The energy cost to produce electric heaters is around 500 kWh per unit.

Production Energy Cost: 500 kWh per unit.

For 2-3 electric heaters: 2 units×500 kWh/unit=1,000 kWh2 \text{ units} \times 500 \text{ kWh/unit} = 1,000 \text{ kWh}2 units×500 kWh/unit=1,000 kWh 3 units×500 kWh/unit=1,500 kWh3 \text{ units} \times 500 \text{ kWh/unit} = 1,500 \text{ kWh}3 units×500 kWh/unit=1,500 kWh

5. Transportation Energy Cost

Assumption: Transportation energy cost is about 1% of the production energy cost for these components.

Total Energy Cost

Summing up the production and transportation energy costs for all components:

Production Energy Cost:

Solar Panels: 22,500 to 25,000 kWh
Battery Storage: 180 to 300 kWh
Inverter: 12,000 to 15,000 kWh
Electric Heaters: 1,000 to 1,500 kWh

Transportation Energy Cost:

Total Production Energy Cost: (22,500 + 180 + 12,000 + 1,000) to (25,000 + 300 + 15,000 + 1,500) Total Production Energy Cost=35,680 to 41,800 kWh\text{Total Production Energy Cost} = 35,680 \text{ to } 41,800 \text{ kWh}Total Production Energy Cost=35,680 to 41,800 kWh
Total Transportation Energy Cost: 1% of Total Production Energy Cost Total Transportation Energy Cost=0.01×35,680 to 41,800 kWh\text{Total Transportation Energy Cost} = 0.01 \times 35,680 \text{ to } 41,800 \text{ kWh}Total Transportation Energy Cost=0.01×35,680 to 41,800 kWh Total Transportation Energy Cost=356.8 to 418 kWh\text{Total Transportation Energy Cost} = 356.8 \text{ to } 418 \text{ kWh}Total Transportation Energy Cost=356.8 to 418 kWh

Total Energy Cost (Production + Transportation):

Total Energy Cost=35,680 to 41,800 kWh+356.8 to 418 kWh\text{Total Energy Cost} = 35,680 \text{ to } 41,800 \text{ kWh} + 356.8 \text{ to } 418 \text{ kWh}Total Energy Cost=35,680 to 41,800 kWh+356.8 to 418 kWh Total Energy Cost=36,036.8 to 42,218 kWh\text{Total Energy Cost} = 36,036.8 \text{ to } 42,218 \text{ kWh}Total Energy Cost=36,036.8 to 42,218 kWh

Conclusion

The estimated energy cost to manufacture all the components of a solar power system (including solar panels, batteries, an inverter, and electric heaters) and get them onsite is approximately 36,036.8 to 42,218 kWh. This estimate includes both production and transportation energy costs.

now please make a simple chart comparing the energy and carbon cost for this solar system and the wood fired heater

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Here’s a simple chart comparing the energy and carbon costs for the solar power system and the wood-fired heater. The chart illustrates the following:

Energy Cost (kWh):
- Wood Heater: 205 kWh
- Solar System: 39,200 kWh (average of the estimated range)
Carbon Cost (kg CO2):
- Wood Heater: 68 kg CO2
- Solar System: 42,500 kg CO2 (average of the estimated range)

The chart shows that while the wood heater has significantly lower energy and carbon costs, the solar system, despite its higher initial costs, provides a renewable and cleaner energy source over its lifespan.

ok now let’s assume that cost of sunlight is nil and the cost of wood is $1/kg… what will be the cost of running the stove over 20 years?

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To calculate the cost of running the wood stove over 20 years, we’ll need to consider the cost of the wood consumed.

Assumptions:

The stove is used on average for 4 hours per day for half the year (182.5 days).
The stove consumes 2.5 kg of wood per hour.
The cost of wood is $1/kg.
No other maintenance or operational costs are considered for simplicity.

Annual Wood Consumption

Wood consumption per day=2.5 kg/hour×4 hours/day=10 kg/day\text{Wood consumption per day} = 2.5 \text{ kg/hour} \times 4 \text{ hours/day} = 10 \text{ kg/day}Wood consumption per day=2.5 kg/hour×4 hours/day=10 kg/day Annual wood consumption=10 kg/day×182.5 days/year=1,825 kg/year\text{Annual wood consumption} = 10 \text{ kg/day} \times 182.5 \text{ days/year} = 1,825 \text{ kg/year}Annual wood consumption=10 kg/day×182.5 days/year=1,825 kg/year

Annual Cost of Wood

Annual cost of wood=1,825 kg/year×$1/kg=$1,825\text{Annual cost of wood} = 1,825 \text{ kg/year} \times \$1/\text{kg} = \$1,825Annual cost of wood=1,825 kg/year×$1/kg=$1,825

Cost Over 20 Years

Cost over 20 years=$1,825×20=$36,500\text{Cost over 20 years} = \$1,825 \times 20 = \$36,500Cost over 20 years=$1,825×20=$36,500

Conclusion

The cost of running the wood stove over 20 years, assuming the cost of wood is $1/kg, would be $36,500.

and let’s also assume the lifespan of the stove is 10 years and the solar is 20 years, cost of the wood stove is $500 initially and replacement in 10 years is $1250

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To calculate the total cost of running the wood stove and the solar power system over 20 years, we need to include the initial costs, maintenance, and replacement costs.

Wood Stove Costs

Initial Cost: $500
Replacement Cost after 10 years: $1250
Annual Wood Cost: $1825

Total Cost for Wood Stove Over 20 Years

Year 0: Initial purchase: $500
Year 1-10: Annual wood cost: $1825/year
Year 10: Replacement cost: $1250
Year 11-20: Annual wood cost: $1825/year

Calculation:

Initial Cost=$500\text{Initial Cost} = \$500Initial Cost=$500 Replacement Cost=$1250\text{Replacement Cost} = \$1250Replacement Cost=$1250 Total Wood Cost (20 years)=20×1825=$36,500\text{Total Wood Cost (20 years)} = 20 \times 1825 = \$36,500Total Wood Cost (20 years)=20×1825=$36,500

Total Cost for Wood Stove=$500+$1250+$36,500=$38,250\text{Total Cost for Wood Stove} = \$500 + \$1250 + \$36,500 = \$38,250Total Cost for Wood Stove=$500+$1250+$36,500=$38,250

Solar Power System Costs

Initial Cost: $81,100 to $126,000 (using the lower end for this example)
Lifespan: 20 years
Operating Cost: Assumed to be negligible for this calculation

Calculation:

Total Cost for Solar Power System=$81,100\text{Total Cost for Solar Power System} = \$81,100Total Cost for Solar Power System=$81,100

Summary of Total Costs Over 20 Years

Wood Stove: $38,250
Solar Power System: $81,100

Conclusion

The total cost of running the wood stove over 20 years, including the initial cost, replacement cost, and cost of wood, is $38,250.
The total cost of the solar power system over 20 years is $81,100.

The wood stove is cheaper over the 20-year period in terms of direct financial costs, but this does not account for externalities such as environmental impact, health costs, or potential increases in wood prices. The solar power system, while having a higher initial cost, offers a renewable and potentially cleaner energy solution over its lifespan.

ok, let’s now compare in a chart the Financial, Energy and Carbon Costs of these 2 systems

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Here’s the comparison chart illustrating the Financial, Energy, and Carbon Costs for the two systems:

Wood Stove

Financial Cost: $38,250
Energy Cost: 205 kWh
Carbon Cost: 68 kg CO2

Solar System

Financial Cost: $81,100
Energy Cost: 39,200 kWh
Carbon Cost: 42,500 kg CO2

The chart highlights the significant differences in each cost type between the wood stove and the solar system. The wood stove has lower financial, energy, and carbon costs over 20 years compared to the solar system, but the solar system provides a renewable and cleaner energy solution over its lifespan.

Home Heating… Wood Combustion vs Home Solar?

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