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I think the article is talking about customers who buy their own solar installations. The thing is, no system is available (afaik) that is 24/7 solar power (bat

I think the article is talking about customers who buy their own solar installations. The thing is, no system is available (afaik) that is 24/7 solar power (batteries add a massive cost to user solar installations) so the only way for you to have power at all times is to sell the surplus generated solar back to the utility (which is where the engineering problems come in) during peak solar hours and using the gird off peak.

cinquemb 14y ago
Well the tech for batteries is getting cheaper and better. Check out this Hak5 rig of van with PV and batteries: http://www.youtube.com/watch?v=tWmCpt2KXOs http://www.youtube.com/watch?v=tWmCpt2KXOs From this, it is not hard to imagine if one scaled this setup one could be off the grid now.
- quantumstate 14y ago
  I was recently in rural South Sudan, at a place where there are no power lines within 80 miles. So the systems they use must be off the grid by necessity. There were several PV and battery setups there which worked pretty well. Obviously you need to be careful with the amount of power that you use, but it can run computers, TV and lighting with a reasonable setup. There was a computer lab at one installation which had one desktop machine acting as a server and about 15 thin clients to keep the power usage low.
  - cinquemb 14y ago
    Thats why i think CSP and thermal storage (via molten salts KNO3+NaNO3) might work better in the long run (at least in an environment with an atmosphere).
criley 14y ago
Yes! But in that paradigm, where you generate 80%+ of your needed energy and rely on the grid for the rest, how does that affect the utility? The only difference to them is that you draw less power than you used to. Sure, it would benefit them to learn your habits so they can manage steady power delivery at scale, but they don't get a say in your solar rollout. They don't get to prevent it. They don't get to be skeptical (or if they are, they can't act on it). The person I'm replying to seemed to say that the engineers at utilities are skeptical of this technology and honestly I don't understand how they're relevant, since utilities aren't rolling out the technology, maintaining the technology, etc.
- sp332 14y ago
  But what if you generate 110% of your electricity needs? You would push out more power than is coming in, sometimes literally running the meter backwards.
  - criley 14y ago
    Are we saying that there is no way to prevent power from going backwards back to the utility? I figured what you generated went directly to your storage system, you drew from your storage system OR the grid, or some third part intelligently drew from the grid or your system as necessary. Is it functionally impossible to have solar panels that don't "run the meter backwards?" Because I can see how that would threaten the infrastructure that wasn't designed for it. I mean, I see places like Apple generating all their electricity on location for their new planned office and using the grid as backup. Is Apple sending their excess power back to the utility? Totally different scale, I'm well aware, but just curious.
    - toomuchtodo 14y ago
      Yes, you can configure inverters to not dump excess current back to the utility. You either charge batteries or you dump the power into a load like an electric water heater. In almost all grid-tied scenarios though, you want to sell the power back to the utility. I'm not familiar with commerical operations, as they would fall under power purchase agreements (PPAs), but with residential installations your meter quite literally does spin backwards or a separate meter is used to determine how much power you've sent back to the grid. This is dependent on how the utility compensates you for the power you generate (spin the meter back if its a credit or the same price as what your purchase it from them at, separate meter if the pricing paid to you is different than the retail rate). As the article states, we don't have the issues in the US that Germany has yet, because Germany produces so much more solar energy than in the US. At some point though, questions will need to be answered about who is going to pay for the spinning capacity (likely natural gas generators) that isn't used except for those rare times when the wind isn't blowing, the sun isn't shinning, and you can't drag enough power in from another geographic region over HVDC transmission lines.
schiffern 14y ago
>batteries add a massive cost to user solar installations SolarCity will install a bank of Tesla Motors Li-ion batteries for grid backup and load shifting. This would be financed over the course of the loan (typically 20 years), not all at once. http://www.solarcity.com/residential/energy-storage.aspx http://www.solarcity.com/residential/energy-storage.aspx

cinquemb 14y ago

Well the tech for batteries is getting cheaper and better. Check out this Hak5 rig of van with PV and batteries: http://www.youtube.com/watch?v=tWmCpt2KXOs http://www.youtube.com/watch?v=tWmCpt2KXOs From this, it is not hard to imagine if one scaled this setup one could be off the grid now.

quantumstate 14y ago
I was recently in rural South Sudan, at a place where there are no power lines within 80 miles. So the systems they use must be off the grid by necessity. There were several PV and battery setups there which worked pretty well. Obviously you need to be careful with the amount of power that you use, but it can run computers, TV and lighting with a reasonable setup. There was a computer lab at one installation which had one desktop machine acting as a server and about 15 thin clients to keep the power usage low.
- cinquemb 14y ago
  Thats why i think CSP and thermal storage (via molten salts KNO3+NaNO3) might work better in the long run (at least in an environment with an atmosphere).

criley 14y ago

Yes! But in that paradigm, where you generate 80%+ of your needed energy and rely on the grid for the rest, how does that affect the utility? The only difference to them is that you draw less power than you used to. Sure, it would benefit them to learn your habits so they can manage steady power delivery at scale, but they don't get a say in your solar rollout. They don't get to prevent it. They don't get to be skeptical (or if they are, they can't act on it). The person I'm replying to seemed to say that the engineers at utilities are skeptical of this technology and honestly I don't understand how they're relevant, since utilities aren't rolling out the technology, maintaining the technology, etc.

sp332 14y ago
But what if you generate 110% of your electricity needs? You would push out more power than is coming in, sometimes literally running the meter backwards.
- criley 14y ago
  Are we saying that there is no way to prevent power from going backwards back to the utility? I figured what you generated went directly to your storage system, you drew from your storage system OR the grid, or some third part intelligently drew from the grid or your system as necessary. Is it functionally impossible to have solar panels that don't "run the meter backwards?" Because I can see how that would threaten the infrastructure that wasn't designed for it. I mean, I see places like Apple generating all their electricity on location for their new planned office and using the grid as backup. Is Apple sending their excess power back to the utility? Totally different scale, I'm well aware, but just curious.
  - toomuchtodo 14y ago
    Yes, you can configure inverters to not dump excess current back to the utility. You either charge batteries or you dump the power into a load like an electric water heater. In almost all grid-tied scenarios though, you want to sell the power back to the utility. I'm not familiar with commerical operations, as they would fall under power purchase agreements (PPAs), but with residential installations your meter quite literally does spin backwards or a separate meter is used to determine how much power you've sent back to the grid. This is dependent on how the utility compensates you for the power you generate (spin the meter back if its a credit or the same price as what your purchase it from them at, separate meter if the pricing paid to you is different than the retail rate). As the article states, we don't have the issues in the US that Germany has yet, because Germany produces so much more solar energy than in the US. At some point though, questions will need to be answered about who is going to pay for the spinning capacity (likely natural gas generators) that isn't used except for those rare times when the wind isn't blowing, the sun isn't shinning, and you can't drag enough power in from another geographic region over HVDC transmission lines.

schiffern 14y ago

>batteries add a massive cost to user solar installations SolarCity will install a bank of Tesla Motors Li-ion batteries for grid backup and load shifting. This would be financed over the course of the loan (typically 20 years), not all at once. http://www.solarcity.com/residential/energy-storage.aspx http://www.solarcity.com/residential/energy-storage.aspx