Asklemmy

Not sure if my "notes" apply unless we share similarities in geographic and market.

Backgroud:

• 1\3 of my country is in the arctic circle
• During summer sun hardly sets, during winter is hardly rises (up nort, not at all)
• Energy is produced mainly with Nuclear (main bulk), hydro, wind, solar (lately on the rise), coal (transfered to backup)
• it doesn't get hot, so cooling is rarely needed during summer,
• from may to september electricity is mostly dirt cheap. Nickle and dime stuff. It has even been negative. During winter it's quite expensive.
• most panel systems here use some amount directly but sell most of their production to the grid and then buy it back when there's not enough own production. No batteries involved. Energy broker takes a cut and so does the grid company.

1. Salesmen that have come to my door to sell panel sets use annual average energy price and even that has been exaggerated. It totally ignores that you will be producing most when energy price is lowest. Their sales pitch calculations are designed to be hard to follow and then they rub the wonderous estimates in your face. You can't base a reclamation on unrealized results.

2. People who say that they have saved a ton of money with panels are usually those who have had fixed value pricing and totally ignore the fact that they would have saved most of it during summer time having energy market based pricing, which they now need to have in order to sell their solar juice to the grid and later buy it back. They of course suffer during the winter, but ignore that because that "has nothing to do with panels" (because it's dark and panels are covered in snow.

3. If I'd been connected to the grid, counter-intuitively the panels facing West would the most usefull, not the ones facing South, because they were active when I used the most. In our market the more you can use your own production the better and this high North sun is still somewhat usefull late in the evening.

4. If off-grid, lithum based batteries seem to be the only viable option. They are however a fire hazard. Up here if you store them outside, you need to insulate the space and keep it above freezing from December to March and that takes energy, when it's most expensive. You can dismantle your battery setup and store them unconnected more safely indoors, but that is not for the layman.

This is becoming too long I'll add more later

I'm using 220V/6kW heating element. When used with 60VDC directly from the panels, it's about 0,45kW. No need for control system, since that is too weak to bring the water to boil. It's function is just to decrease the consumption of heating oil. Oil burner is set to start at eavening just before enyone needs hot water and panel output goes down. Oil burner heats the water in the tank to 80ºC. It's about 40-60ºC next morning when the sun rises, depending on the consumption.