Solar energy in Vermont?

Submitted by star_tyger t3_11m4s98 in vermont

With cloud cover virtually all winter, is it possible to have a passive solar greenhouse? Also, I'm considering solar power for both the greenhouse and my home, but how useful is it in the winter, when I would have a greater need for power than in the summer?

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dnstommy t1_jbfwwo9 wrote

Its all about the offset. Vermont makes power companies pay a fair credit for the power you make. So if you over produce in the summer, you can use those credits in the winter.

But VT is nothing like Florida when it comes to solar. 1/3 of the year, I make no power at all.

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they_have_no_bullets t1_jbgfeto wrote

We get our electricity from solar (even in the winter). But for heating the green house, we use geothermal air circulation (fans powered by solar of course). Passive solar thermal doesn't work well in winter, it's actually even less efficient than solar PV used to heat water with resistive coils when it's gets cold. Passive solar thermal is only more efficient than solar PV when it's very sunny out

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Aperron t1_jbgo5km wrote

Replying to dnstommy (#2,187,643)

Keep in mind what you consider fair is also not really all that fair to other rate payers.

On those sunny days when demand isn’t high on the regional grid, the going bulk rates are extremely low, very small fractions of a cent per kwh but net metering forces the utilities to pass up on that deal and instead buy power back from you at close to retail rates.

Much of the time the going market price for a kwh is far less than they’re paying you, but any time your panels are producing, they can’t reject that power and source the cheapest kwh available.

It’s unfortunate because GMPs rates are more than double those in many parts of the country. If they want to continue lobbying for forced electrification, they should be working on getting rates somewhere between 1/2 and 1/4 what they currently are.

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Aperron t1_jbgvoh0 wrote

Replying to vermont4runner (#2,188,900)

It’s almost like all that money being put into residential solar, grid scale solar and battery storage might be better spent building more generation capacity that’s dispatchable on demand. I don’t really care if they have to burn the cutest puppies that ever lived by the rail car load for fuel if it’s cheaper than what we’re doing now.

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star_tyger OP t1_jbgwbo8 wrote

I don't need to be off grid, but I do want to off-the-grid-able. If power goes out, I want to be able to produce our own. Reduced power bills are nice, but I'm more concerned having power when we need it, especially as we're considering going all electric. So I guess I'll have to look into solar and wind, and see what other options there are.

As for the greenhouse, I'm going to have to look into active heat options. Solar power may still work for fans and lighting, though I'll see about hooking into the house system if needed. I don;t see how a climate battery or geothermal is an option, unless the greenhouse heats up enough during the day to have enough heat to store. I also don't know yet if we'll hit rock when we start digging.

Thank you all for your advice/information/experience. You've confirmed my suspicions. Now I need to start thinking of options.

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mrwalrus88 t1_jbh01ya wrote

Replying to star_tyger (#2,188,961)

Having solar doesn't make you off grid able since the solar feeds the grid and you draw from the grid. So if the grid goes out so does your power even if the sun is shining(at least that's how I understand it. If you have a battery storage system if the grid goes out the battery turns on like a generator. I could be wrong but most batteries will give you at best a couple of days of power so if the power goes out for an extended period like we had in December it may not last.

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cbospam1 t1_jbh3xvw wrote

Replying to mrwalrus88 (#2,189,127)

My parents house used to be off grid with solar, when they connected they kept the system and it charges a battery bank before going to the grid. It’s a bank of car batteries that can run the well pump, hot water heater, wifi and a few lights. They could go indefinitely if needed. I’m sure there are more efficient battery systems now. They also have to turn it on manually.

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Howard_Scott_Warshaw t1_jbjkiz0 wrote

Replying to Aperron (#2,188,667)

Not all kWhs are created equally. That's what net metering attempts to help correct. A kWh produced where it's used is more "valuable" than a kWh produced at a gas fired plant 200 miles away that has to go through 8 transformers to get to the load.

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Aperron t1_jbjlfnb wrote

Replying to Howard_Scott_Warshaw (#2,193,163)

Which is also incredibly expensive to install, requires eventual replacement of the most expensive component (the battery), and is finite in capacity. It would be cheaper to install a few gas turbine peaker plants around the state in locations where there is natural gas pipeline infrastructure than to install thousands of home batteries to achieve the same peak demand management results.

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Aperron t1_jbjpb5y wrote

Replying to Howard_Scott_Warshaw (#2,193,362)

The cost savings described in that article compare the cost of covering peaks above our contractually agreed capacity from HydroQuebec with Powerwalls versus needing to purchase the difference at the variable market rates from ISONE when they’re at their absolute highest due to demand.

They are not comparing against the cost of covering that shortfall with local GMP owned gas or even fuel oil fired peakers.

Of course, a site focusing on green energy isn’t going to make that type of comparison in a situation where fossil fuels might provide a cheaper solution.

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Aperron t1_jbjtho2 wrote

Replying to Howard_Scott_Warshaw (#2,193,558)

That’s wonderful. A $40+ million dollar installation, being built in response to a state mandate to build battery storage.

The installation can supply power to a small area for between 3 to 10 hours and then becomes entirely useless once discharged.

Remove the political constraints and I bet the ROI on a gas turbine is much better.

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Howard_Scott_Warshaw t1_jbjyi1u wrote

Replying to Aperron (#2,193,615)

You're acting like fossil fuels aren't subsidized as well, and also forgetting about the blackouts in TX caused by frozen nat. gas pipelines. I'm sure you would agree those plants were "entirely useless".

I would agree, remove subsidies and political constraints and let the technologies fight it out. However this is a bit of a fantasy world, and if it were to happen I believe nuclear would see a resurgence and take over as the prime mover.

Hopefully this discussion is pointless in 20 years once fusion technology takes off.

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Dangerous_Mention_15 t1_jbmp6b4 wrote

Replying to [deleted] (#2,197,631)

My view is it might be better. But you're randomly adding a small amount of power to the grid in an originally unplanned location and doing so at a time when wholesale power is likely very cheap but pulling power back out when wholesale is very expensive and there is a good chance that gas turbines are being brought online to meet the peak load demands. This is likely shifting costs to lower socioeconomic class people. It's not meant as a bash against you, but against the system.

I do fine for myself. I make $400k to $500k per year, I work three days a week, and I have two heat pumps (no solar), etc. But I think the system of marked up electric prices, rebates, subsidies, etc is largely an inefficient wealth transfer program that disproportionately hurts the poorest in VT. I really think it stinks. Residential solar is pretty dumb in this geographic location (total costs per kwh, deaths per kwh, etc.). Nuclear, hydro, wind, and biomass are better contenders.

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