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The OP does not have a single clue about actually using solar. His price per KWH is about 1 order of magnitude off (and then some). I've used 100% solar for t

The OP does not have a single clue about actually using solar. His price per KWH is about 1 order of magnitude off (and then some). I've used 100% solar for the past 2 years and there has not been a single day that I needed a second source of power. Also my system is quite modest. Just 500W of panels and about 600Wh of lithium ion battery (lifepo4) energy storage. The 500W of panels is plenty. Most days I charge my batteries fully before noon. The 600Wh of batteries is enough to get me through 3 days of heavy cloud weather ( you get about 10% of your maximum generation on a heavily clouded day ). This system is for two people using our computers and 3g wireless for the entire day. LED lights at night which are bright and warm, water pump, food processor, stereo, iPad, hella gadgets, raspberry pi backup server, etc etc If I changed something, I'd double the batteries that I use.. going to 24V. You get more of the rated power of the solar panel when using a 24V system. I am considering getting an electric bike & storing extra power there. The total cost of the system was about $800. In the summer I can generate about 2 kWh / sunny day -- I only need about 400Wh / day though. You do the math for the cost per kWh. It's damn cheap.

jacquesm 11y ago
> The OP does not have a single clue about actually using solar. Exactly. It's a total nonsense proposition to offset seasonal swing using battery power. Running a PV system is about conservation first and foremost and some planning second. Your battery is for the day/night cycle and overcast days, not for seasonal variations. Maybe he should run a PV system for a while before writing articles like these.
- raesene4 11y ago
  I think the original article was looking at the proposition of off-grid energy use using purely solar, in which scenario seasonal variations matter From the article "Even with these rough numbers it’s hard to see how anyone living any distance from the Equator is going to be able to justify the cost of installing enough batteries to go off-grid with a domestic rooftop solar PV installation."
  - jacquesm 11y ago
    > Even with these rough numbers it’s hard to see how anyone living any distance from the Equator is going to be able to justify the cost of installing enough batteries to go off-grid with a domestic rooftop solar PV installation. If you go off grid on purely solar your backup is not a battery, your backup is a genset. It's a nonsense proposition leading to nonsense conclusions based on nonsense numbers. Very tiring.
    - raesene4 11y ago
      I'd agree, I was just pointing out the basis that the author was coming from which was the reason why he was considering seasonal variations in battery calculations. With that said, from reading some articles about off-grid living, it's not outwith the bounds of possibility that people are looking at pure solar (or pure renewable anyway) off-grid living, for priniple-based reasons , rather than a more pragmatic rationale.
      - jacquesm 11y ago
        Only if they don't care about their lives. Look, I've lived off the grid for a number of years. 99% of the time things work just fine and all your plans come out. And then, in the middle of January there is a 9 day spell without wind and solar and you're going to have to fire up the genset. Tough, but preferable over having all your waterlines freeze due to 'principles'. Principles are nice to have but when you go off-grid out of principle the one principle you don't want to throw overboard is reliability and a good generator is worth gold when everything else you carefully planned out fails. If there is one thing that you can predict about the weather then it is that it is unpredictable.
        codecamper 11y ago
        I guess a genset doesn't add much to the final bill?
        jacquesm 11y ago
rahimnathwani 11y ago
"600W of energy storage" Do you mean 600Wh?
- codecamper 11y ago
  Oops, yes. Edited & corrected. Thank you.
kalleboo 11y ago
So do you cook with gas then?
- codecamper 11y ago
  Yes, we cook with gas. If this were a more permanent home (we live in a 20 foot camper, currently in Morocco), then I'd look into replacing the fridge and the stove with electric versions. The fridge would probably double our power requirements. Add in a stove and we may need 3x our requirements. The total bill would still be pretty cheap, but I may be running out of roof space on a camper this size.
JupiterMoon 11y ago
Do you use a gas fridge and stove?

jacquesm 11y ago

> The OP does not have a single clue about actually using solar. Exactly. It's a total nonsense proposition to offset seasonal swing using battery power. Running a PV system is about conservation first and foremost and some planning second. Your battery is for the day/night cycle and overcast days, not for seasonal variations. Maybe he should run a PV system for a while before writing articles like these.

raesene4 11y ago
I think the original article was looking at the proposition of off-grid energy use using purely solar, in which scenario seasonal variations matter From the article "Even with these rough numbers it’s hard to see how anyone living any distance from the Equator is going to be able to justify the cost of installing enough batteries to go off-grid with a domestic rooftop solar PV installation."
- jacquesm 11y ago
  > Even with these rough numbers it’s hard to see how anyone living any distance from the Equator is going to be able to justify the cost of installing enough batteries to go off-grid with a domestic rooftop solar PV installation. If you go off grid on purely solar your backup is not a battery, your backup is a genset. It's a nonsense proposition leading to nonsense conclusions based on nonsense numbers. Very tiring.
  - raesene4 11y ago
    I'd agree, I was just pointing out the basis that the author was coming from which was the reason why he was considering seasonal variations in battery calculations. With that said, from reading some articles about off-grid living, it's not outwith the bounds of possibility that people are looking at pure solar (or pure renewable anyway) off-grid living, for priniple-based reasons , rather than a more pragmatic rationale.
    - jacquesm 11y ago
      Only if they don't care about their lives. Look, I've lived off the grid for a number of years. 99% of the time things work just fine and all your plans come out. And then, in the middle of January there is a 9 day spell without wind and solar and you're going to have to fire up the genset. Tough, but preferable over having all your waterlines freeze due to 'principles'. Principles are nice to have but when you go off-grid out of principle the one principle you don't want to throw overboard is reliability and a good generator is worth gold when everything else you carefully planned out fails. If there is one thing that you can predict about the weather then it is that it is unpredictable.
      - codecamper 11y ago
        I guess a genset doesn't add much to the final bill?
        jacquesm 11y ago

rahimnathwani 11y ago

"600W of energy storage" Do you mean 600Wh?

codecamper 11y ago
Oops, yes. Edited & corrected. Thank you.

kalleboo 11y ago

So do you cook with gas then?

codecamper 11y ago
Yes, we cook with gas. If this were a more permanent home (we live in a 20 foot camper, currently in Morocco), then I'd look into replacing the fridge and the stove with electric versions. The fridge would probably double our power requirements. Add in a stove and we may need 3x our requirements. The total bill would still be pretty cheap, but I may be running out of roof space on a camper this size.

JupiterMoon 11y ago

Do you use a gas fridge and stove?