Summary:
I'm trying to decide to either get 10 panels or 20 panels for a net metering solar install in MA. 20 panels is the max my roof can fit. The difference is roughly $10k in price. 10 (400w QCell w/Enphase microinverters) panels will provide %135 of my current electrical needs. 20 panels will be well over double what I currently need. My initial goal was to have no gas or electric bills. Even with 20 panels I don't think that's possible so is it even worth it?
The Details:
I live in MA, which has 1:1 net metering. Last year I used 3,700kw of electricity for a 2,100sft house. My roof is pointed south with no obstructions. The house uses gas for heat, water, oven, range, dryer.
My gas furnace is old and I thought I would switch to ground source heat pump since it should be more efficient than air source heat pumps. I've had various companies inform me that the electrical usage of a ground source heat pump for my house would range from 3,000kw to 6,000kw per year.
My electrical use would then range from 6,700kw to 9,700kw. 20 panels are estimated to annually produce roughly 9,680kw, which might be enough to offset the electricity bill. That's just switching heating from gas to electric. If I switch all the other gas appliances I'm not so sure I'll be able to be bill free. Gas is relatively cheap in MA where as electricity is on the higher end in the US at around $0.24/Kw.
If I forego the ground source heat pump I really don't need 20 panels. I thought I'd then get 14 panels to have a bit more head room. If I needed more for expansion then I could get 6 more panels added then. The installer though says that at a minimum they need to install 8 to 10 panels for it to be worth their time the second time around. Most likely that will be 10 panels as time passes. That then gets me to using either 10 or 20 panels.
10 panels will meet my current needs. If I go with a gas furnace in the future I don't foresee a major increase in electrical use. I would like an EV but I don't see it happening anytime in the next 5 years. After 10 years the panels degrade to 90% production. I should still be over producing and meet 120% of my current needs. The ROI is around 8 years factoring in electricity price increases.
20 panels though would allow me to take advantage of the 26% tax incentive this year as well as being cheaper to install doing it all at once. The ROI though would be close to 17 years. Over production will keep building credit on my account with NationGrid. From what I've heard, in MA those credits never expire so I could build up credits for years if I don't use them. I think I'm able to cash out the credits, but it would be at the wholesale rate, which is probably a few pennies per kw, instead of the retail rate.
The cost difference is $10k. That $10 either goes into solar panels with a long ROI or I could invest that in the market. I'm pretty sure the market will have better returns after 17 years.
My heart wants to do 20 panels, but I'm having a difficult time justifying it. Most likely I will get 10 panels but it will bug me that if I ever expand it's going to be a headache and be overall more expensive. If I go with 20 panels is there any way to use the extra production that can shorten my ROI? I looked into mining but my extra production would only be a drop in the bucket with what mining requires.
I'm trying to decide to either get 10 panels or 20 panels for a net metering solar install in MA. 20 panels is the max my roof can fit. The difference is roughly $10k in price. 10 (400w QCell w/Enphase microinverters) panels will provide %135 of my current electrical needs. 20 panels will be well over double what I currently need. My initial goal was to have no gas or electric bills. Even with 20 panels I don't think that's possible so is it even worth it?
The Details:
I live in MA, which has 1:1 net metering. Last year I used 3,700kw of electricity for a 2,100sft house. My roof is pointed south with no obstructions. The house uses gas for heat, water, oven, range, dryer.
My gas furnace is old and I thought I would switch to ground source heat pump since it should be more efficient than air source heat pumps. I've had various companies inform me that the electrical usage of a ground source heat pump for my house would range from 3,000kw to 6,000kw per year.
My electrical use would then range from 6,700kw to 9,700kw. 20 panels are estimated to annually produce roughly 9,680kw, which might be enough to offset the electricity bill. That's just switching heating from gas to electric. If I switch all the other gas appliances I'm not so sure I'll be able to be bill free. Gas is relatively cheap in MA where as electricity is on the higher end in the US at around $0.24/Kw.
If I forego the ground source heat pump I really don't need 20 panels. I thought I'd then get 14 panels to have a bit more head room. If I needed more for expansion then I could get 6 more panels added then. The installer though says that at a minimum they need to install 8 to 10 panels for it to be worth their time the second time around. Most likely that will be 10 panels as time passes. That then gets me to using either 10 or 20 panels.
10 panels will meet my current needs. If I go with a gas furnace in the future I don't foresee a major increase in electrical use. I would like an EV but I don't see it happening anytime in the next 5 years. After 10 years the panels degrade to 90% production. I should still be over producing and meet 120% of my current needs. The ROI is around 8 years factoring in electricity price increases.
20 panels though would allow me to take advantage of the 26% tax incentive this year as well as being cheaper to install doing it all at once. The ROI though would be close to 17 years. Over production will keep building credit on my account with NationGrid. From what I've heard, in MA those credits never expire so I could build up credits for years if I don't use them. I think I'm able to cash out the credits, but it would be at the wholesale rate, which is probably a few pennies per kw, instead of the retail rate.
The cost difference is $10k. That $10 either goes into solar panels with a long ROI or I could invest that in the market. I'm pretty sure the market will have better returns after 17 years.
My heart wants to do 20 panels, but I'm having a difficult time justifying it. Most likely I will get 10 panels but it will bug me that if I ever expand it's going to be a headache and be overall more expensive. If I go with 20 panels is there any way to use the extra production that can shorten my ROI? I looked into mining but my extra production would only be a drop in the bucket with what mining requires.
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