7 ms·

You can't run loads from cells directly, you need a battery and inverters. Or every cloud will fluctuate the voltage and watts massively and your electronics wi

by homero 9y ago

You can't run loads from cells directly, you need a battery and inverters. Or every cloud will fluctuate the voltage and watts massively and your electronics will fry. In the olden days, flickering incandescent would be fine.

dom0 9y ago
You don't need inverters, strictly speaking. For some applications the battery voltage is just fine.
rwmj 9y ago
As the other reply says, it's quite possible to power electronics from the cells (but not directly). What you need to look for are the types of regulators and batteries used in caravans. Of course you cannot connect such a system directly to the grid.
SigmundA 9y ago
Not exactly accurate. My Dad has a 7kw array grid-tie no battery system in FL. It has a single emergency outlet that will provide up 1500w when the grid is down. With the power being down last week from Irma it was able to output at least a 1000w load even with heavy overcast. It will off course shut off if it can't provide the attached load. If you have a solar system for home its going to have an inverter, but most likely no batteries, some inverters can provide emergency power without them. Batteries obviously work much better for that scenario allowing them to buffer energy. But nearly all grid tie systems installed do not have batteries due to extra cost and maintenance.
- dundercoder 9y ago
  7kw? Amazing! How large is the array? (sq ft) How much did that set him back?
  - grecy 9y ago
    In Australia 5kw is extremely common (20 250 watt panels) - out of pocket it's ~$5000 AUD. Now that 280 watt panels are becoming common, up to 7kw is a "standard" install.
    - quickthrower2 9y ago
      But you need three phase to go beyond 5kw if I understand correctly
      - grecy 9y ago
        I think you have to get permission to ensure that not too many people in your immediate area have over 5kw, otherwise the grid in that area might not be able to handle so much being pushed back in without upgrades. I don't know about three phase.
  - SigmundA 9y ago
    Its half a barn roof, I believe its was around $15k installed. Main issue I have seen with the law in FL for them is that they are net metered but the power bill can't go negative. So if they produce more than they use the power company doesn't have to pay them for it, also they always get a service charge no matter what. So their power bill ends up being about $20 a month no matter what which is just the service charge.
    - blacksmith_tb 9y ago
      That's how net metering works for me in Oregon, too - I earn credits by over-producing all summer, and then use some of them up until Jan 1, as they won't roll over year-to-year. As a result I gave power away for free to the grid for several years, but now I have a plug-in hybrid to soak up the surplus.
- maxerickson 9y ago
  Does his system meet code? If so, it demonstrates that the article is, uh, not well researched.
  - SigmundA 9y ago
    Yes it was completely done to code. Here is the explanation of his inverter: http://www.smainverted.com/how-to-explain-secure-power-supply-to-homeowners/ http://www.smainverted.com/how-to-explain-secure-power-suppl... The inverter doesn't backfeed for emergency power, it just has a separate output wired to a single outlet for emergency power.
    - maxerickson 9y ago
      Yeah I linked that page a few days ago (https://news.ycombinator.com/item?id=15247172 https://news.ycombinator.com/item?id=15247172 ). But the article would have us believe that it is illegal to use those inverters in Florida.
- homero 9y ago
  True but look at the percentage, a smaller setup would have very little useable load

by homero 9y ago

dom0 9y ago

You don't need inverters, strictly speaking. For some applications the battery voltage is just fine.

rwmj 9y ago

As the other reply says, it's quite possible to power electronics from the cells (but not directly). What you need to look for are the types of regulators and batteries used in caravans. Of course you cannot connect such a system directly to the grid.

SigmundA 9y ago

Not exactly accurate. My Dad has a 7kw array grid-tie no battery system in FL. It has a single emergency outlet that will provide up 1500w when the grid is down. With the power being down last week from Irma it was able to output at least a 1000w load even with heavy overcast. It will off course shut off if it can't provide the attached load. If you have a solar system for home its going to have an inverter, but most likely no batteries, some inverters can provide emergency power without them. Batteries obviously work much better for that scenario allowing them to buffer energy. But nearly all grid tie systems installed do not have batteries due to extra cost and maintenance.

dundercoder 9y ago
7kw? Amazing! How large is the array? (sq ft) How much did that set him back?
- grecy 9y ago
  In Australia 5kw is extremely common (20 250 watt panels) - out of pocket it's ~$5000 AUD. Now that 280 watt panels are becoming common, up to 7kw is a "standard" install.
  - quickthrower2 9y ago
    But you need three phase to go beyond 5kw if I understand correctly
    - grecy 9y ago
      I think you have to get permission to ensure that not too many people in your immediate area have over 5kw, otherwise the grid in that area might not be able to handle so much being pushed back in without upgrades. I don't know about three phase.
- SigmundA 9y ago
  Its half a barn roof, I believe its was around $15k installed. Main issue I have seen with the law in FL for them is that they are net metered but the power bill can't go negative. So if they produce more than they use the power company doesn't have to pay them for it, also they always get a service charge no matter what. So their power bill ends up being about $20 a month no matter what which is just the service charge.
  - blacksmith_tb 9y ago
    That's how net metering works for me in Oregon, too - I earn credits by over-producing all summer, and then use some of them up until Jan 1, as they won't roll over year-to-year. As a result I gave power away for free to the grid for several years, but now I have a plug-in hybrid to soak up the surplus.
maxerickson 9y ago
Does his system meet code? If so, it demonstrates that the article is, uh, not well researched.
- SigmundA 9y ago
  Yes it was completely done to code. Here is the explanation of his inverter: http://www.smainverted.com/how-to-explain-secure-power-supply-to-homeowners/ http://www.smainverted.com/how-to-explain-secure-power-suppl... The inverter doesn't backfeed for emergency power, it just has a separate output wired to a single outlet for emergency power.
  - maxerickson 9y ago
    Yeah I linked that page a few days ago (https://news.ycombinator.com/item?id=15247172 https://news.ycombinator.com/item?id=15247172 ). But the article would have us believe that it is illegal to use those inverters in Florida.
homero 9y ago
True but look at the percentage, a smaller setup would have very little useable load