What size Solar Panel Needed for an Electric Fish House Heater?

[TroutYammer]

I have been thinking about getting a solar panel to run an electric heater for my fish house. Most heaters on the web are 115V and draw about 13.5Amps. Anybody know how big of a solar panel I need to run that? Or any other ideas would be greatly appreciated.

[McGurk]

HUGE ones. The 12 volt RV panels I'm looking at for you online are 7 amp/125 watt units. The base unit is $1,050, and you'd have to get another one to get to 14 amps, that would be another $950. They are each 58" by 26", and you'd need 2 of them, plus a battery system to run as a buffer. I'd look at other options for heat if I were you.

Electic heat is one of the most inefficient heat sources out there. For example: A simple 2-slice Toaster can draw as much amperage as a small microvave, and many times more than even the least efficient 36" tube TV.

Some other appliances, for reference:

Typical Amperages of Various Appliances

Appliance or Electronic Equipment- Estimated Amps

Coffee Maker- 5-8 Amps

Compact Disc Player- 1 Amp

Computer (Laptop)- 2-3 Amps

Converter- 1-8 Amps

Crock Pot- 1-2 Amps

Curling Iron- <1 Amp

Drill- 2-6 Amps

Electric Blanket- 0.5-1.5 Amps

Electric Fan- 1 Amp

Electric Water Heater- 9-13 Amps

Electric Skillet- 6-12 Amps

Hair Dryer- 5-12 Amps

Iron- 5-10 Amps

Light (60 watt % 120V)- <1 Amp

Microwave- 8-13 Amps

Microwave (Convection Oven)- 13 Amps

Refrigerator in AC mode- 5-8 Amps

Space Heater- 8-13 Amps

Television- 1.5-4 Amps

Toaster- 7-10 Amps

Vacuum (handheld)- 2-6 Amps

VCR- 1-2 Amps

Washer/Dryer- 14-16Amps

[Lip_Ripper Guy]

HUGE!

I have a small electric heater that I hooked up to my 2000 watt generator. It maxed out the generator, and that little heater couldn't even come close to heating the fish house. By the time you got a system figured out, your entire roof would be solar panels, and you'd spend MANY years worth of propane fill ups.

[heat checker]

We run 2 electrics off a 3500w generator, also fire up the buddy. Within minutes its warm enough to turn off buddy and turn down electrics to lower settings.

[leech~~]

11 hours ago, Fasterok said:

All things considered, I'm happy if we can pollute the planet a bit less than we do now. To use these less energy, I even ordered a miniature solar panel like this for myself. We'll all get there eventually.

Haven't you listened to any of the Climate Accord? Bidens going to save the world. Start burning rubber tires again! 

[BobT]

On 12/28/2010 at 2:33 PM, McGurk said:

HUGE ones. The 12 volt RV panels I'm looking at for you online are 7 amp/125 watt units. The base unit is $1,050, and you'd have to get another one to get to 14 amps, that would be another $950. They are each 58" by 26", and you'd need 2 of them, plus a battery system to run as a buffer. I'd look at other options for heat if I were you.

 

Electic heat is one of the most inefficient heat sources out there. For example: A simple 2-slice Toaster can draw as much amperage as a small microvave, and many times more than even the least efficient 36" tube TV.

 

Some other appliances, for reference:

 

Typical Amperages of Various Appliances

Appliance or Electronic Equipment- Estimated Amps

Coffee Maker- 5-8 Amps

Compact Disc Player- 1 Amp

Computer (Laptop)- 2-3 Amps

Converter- 1-8 Amps

Crock Pot- 1-2 Amps

Curling Iron- <1 Amp

Drill- 2-6 Amps

Electric Blanket- 0.5-1.5 Amps

Electric Fan- 1 Amp

Electric Water Heater- 9-13 Amps

Electric Skillet- 6-12 Amps

Hair Dryer- 5-12 Amps

Iron- 5-10 Amps

Light (60 watt % 120V)- <1 Amp

Microwave- 8-13 Amps

Microwave (Convection Oven)- 13 Amps

Refrigerator in AC mode- 5-8 Amps

Space Heater- 8-13 Amps

Television- 1.5-4 Amps

Toaster- 7-10 Amps

Vacuum (handheld)- 2-6 Amps

VCR- 1-2 Amps

Washer/Dryer- 14-16Amps

Agreed. Electric heat is one of the most, if not the most, expensive ways to heat an area. I created a spread sheet that compares different systems. It takes into account the fuel cost per unit, BTU output per fuel unit, and the efficiency rating of the heating system (when new). System efficiencies usually degrade over time although this can be minimized with good maintenance. 

 

We have three heating systems in our house - The two primary systems are a forced air fuel-oil and baseboard electric on a dual-fuel plan throughout the house. We also have an LP fireplace in our living room. The dual-fuel electric rate is half the rate of our regular electricity. The caveat is that during periods of high demand, the power company can and will turn off the electric supply to the system.

 

On October 5th of this year I ran my comparisons.

• #2 home heating oil was $3.83/gallon. (~139,600 BTU per gallon and 83% efficiency rated furnace)
• LP gas was $1.70/gallon. (~91,330 BTU per gallon and 86% efficiency rated fireplace)
• Dual-fuel electric was $0.057/kWh. (~3,412 BTU per kWh and 100% efficiency rated heaters)

The calculated cost per 1 million BTU for each system...

• Home heating oil $33.05 per 1M BTU.
• LP gas - $21.64 per 1M BTU.
• Electricity - $16.71 per 1M BTU. 

I do not know what the current prices are for fuel oil and LP gas so these numbers are about 6-weeks old. As you can see, if I was paying full price for the electricity it would cost more ($16.71 x 2 = $33.42) than using the fuel-oil furnace to heat our home. 

[BobT]

Little off topic but here's something else I'll share.  I decided to look into adding solar electric for our home. I got bids from two different electrical contractors and the results were very similar. Here's a bullet point list of some factors.

• To provide all the power we would need including heating our home with electricity, we would need about a 40Kw system. That is the maximum size allowed that can still qualify for the tax incentive. 
• The price was upwards of $135,000.00, less a 30% tax incentive ($40,500.00) that could be claimed over a 5-year period. 
• The problem with doing this is that because we get our electricity for the dual-fuel electric heat at half price, solar can't compete so I decided to just look at supplying our normal average needs, which is about 900kWh per month  or about 10,000Kw annually. Both companies quoted slightly larger systems to account for system degradation and reduced productivity periods such as cloudy days, snow on the panels, etc.
• The price for this system was approximately $36,000.00 with a 30% tax credit leaving net cost at $26,500.00.
• One of the contractors offered a 2% low interest loan payment plan.
• Assuming I'd pay the amount equivalent to the tax credit as down payment and borrow the difference of $26,500.00 over a 10-year loan, my total system out-of-pocket cost would be approximately $29,250.00.
• Next I considered the price of electricity. Over the past 20 years, our electric rates increased by an average of about 3% per year. Projecting a similar trend to continue I calculated that it would take approximately 22 years to reach my break-even point.
• This did not account for maintenance costs over those same 22 years, however, both contractors offered full 20-year warranty (bumper to bumper as one described it) including hail and wind damage. 
• Because of current laws, this system would not require a back-up battery. This is because of net metering laws the power utility is required to purchase or credit our account for all excess energy produced. In this way, during the summer months, the system would over produce by quite a bit and then during the lean production winter periods, we'd use the cash or credits to pay for our electric shortfall. 
• One concern to note is that currently, due to the lack of production vs power demand, the electric companies are in need of the excess energy so buying it from me at last year's price just makes more power available to them for sale now. However, as more and more people install solar systems, the demand for electricity from utility companies will decrease and they will likely push to change the laws regarding the purchase/credit of excess electricity. This is already coming to fruition in California where power companies are pushing for reductions in net metering laws and encouraging users to install battery backup systems instead. If something like this happens after I've installed my solar system, it would add more cost.

 

Bottom line is that at nearly 64-years old, and assuming the current net metering laws don't change, I wouldn't break even until I'm 86. I figure I'd be lucky to live long enough to realize any benefits unless the cost of electricity goes up a lot faster than 3% per year, which doesn't sound plausible if more and more people become self-sufficient, reducing the demand for electricity. I figure if I was 10 years or more younger, it would warrant a more serious look. 

 

When I asked about the projected life expectancy of the system both contractors said the same thing. The panels and inverters have a life expectancy of about 50 years. Degradation of the system is expected to be less than 1% per year. Both companies offered 20-year warranty of components including hail and wind damage. Both were rooftop installations. Ground level installations, which I would have preferred, would add about $10,000.00 to the cost.

Edited November 26, 2022 by BobT

[leech~~]

8 hours ago, BobT said:

Little off topic but here's something else I'll share.  I decided to look into adding solar electric for our home. I got bids from two different electrical contractors and the results were very similar. Here's a bullet point list of some factors.

• To provide all the power we would need including heating our home with electricity, we would need about a 40Kw system. That is the maximum size allowed that can still qualify for the tax incentive. 
• The price was upwards of $135,000.00, less a 30% tax incentive ($40,500.00) that could be claimed over a 5-year period. 
• The problem with doing this is that because we get our electricity for the dual-fuel electric heat at half price, solar can't compete so I decided to just look at supplying our normal average needs, which is about 900kWh per month  or about 10,000Kw annually. Both companies quoted slightly larger systems to account for system degradation and reduced productivity periods such as cloudy days, snow on the panels, etc.
• The price for this system was approximately $36,000.00 with a 30% tax credit leaving net cost at $26,500.00.
• One of the contractors offered a 2% low interest loan payment plan.
• Assuming I'd pay the amount equivalent to the tax credit as down payment and borrow the difference of $26,500.00 over a 10-year loan, my total system out-of-pocket cost would be approximately $29,250.00.
• Next I considered the price of electricity. Over the past 20 years, our electric rates increased by an average of about 3% per year. Projecting a similar trend to continue I calculated that it would take approximately 22 years to reach my break-even point.
• This did not account for maintenance costs over those same 22 years, however, both contractors offered full 20-year warranty (bumper to bumper as one described it) including hail and wind damage. 
• Because of current laws, this system would not require a back-up battery. This is because of net metering laws the power utility is required to purchase or credit our account for all excess energy produced. In this way, during the summer months, the system would over produce by quite a bit and then during the lean production winter periods, we'd use the cash or credits to pay for our electric shortfall. 
• One concern to note is that currently, due to the lack of production vs power demand, the electric companies are in need of the excess energy so buying it from me at last year's price just makes more power available to them for sale now. However, as more and more people install solar systems, the demand for electricity from utility companies will decrease and they will likely push to change the laws regarding the purchase/credit of excess electricity. This is already coming to fruition in California where power companies are pushing for reductions in net metering laws and encouraging users to install battery backup systems instead. If something like this happens after I've installed my solar system, it would add more cost.

 

Bottom line is that at nearly 64-years old, and assuming the current net metering laws don't change, I wouldn't break even until I'm 86. I figure I'd be lucky to live long enough to realize any benefits unless the cost of electricity goes up a lot faster than 3% per year, which doesn't sound plausible if more and more people become self-sufficient, reducing the demand for electricity. I figure if I was 10 years or more younger, it would warrant a more serious look. 

 

When I asked about the projected life expectancy of the system both contractors said the same thing. The panels and inverters have a life expectancy of about 50 years. Degradation of the system is expected to be less than 1% per year. Both companies offered 20-year warranty of components including hail and wind damage. Both were rooftop installations. Ground level installations, which I would have preferred, would add about $10,000.00 to the cost.

Yeah, I would let the next owners spent the money and you can take your wife to Hawaii with the money you didn't spend!