Remember when we were told that privatisation of power generation would lower prices?

  • Dave@lemmy.nzM
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    3 months ago

    But if you have these huge industrial buildings, surely the company is not going to be able to justify covering the whole thing in panels then feeding back to the grid. They would only build what they needed to cover their usage, which is probably only a fraction of their roof.

    • absGeekNZ@lemmy.nz
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      3 months ago

      Depends on the industry…they can use a huge amount of power.

      But feeding into the grid is not always the goal, reducing the amount they consume is the same from an energy balance point of view.

      e.g. where I work, we have about 4 acres (16,000m^2) of suitable roof, we could generate approx 16MW, we draw ~3 - 4 times that from the grid constantly. During the generating time we would be taking 16MW less from the grid.

      • Dave@lemmy.nzM
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        3 months ago

        Ah wow, yeah I can see that being a good idea.

        I’ve always wondered why solar is popular in home use applications and not so popular in businesses. Since solar generates during the day, surely it makes sense to install for businesses whose peak usage is during the day, not residential whose peak usage is early morning or in the evening.

        • absGeekNZ@lemmy.nz
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          3 months ago

          Lots of reasons. Non-core business, long/uncertain payback (if power prices take a dive the payback extends), high upfront cost, a lot of regulation around feeding power into the grid.

          • Dave@lemmy.nzM
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            3 months ago

            Shouldn’t those apply to residential too?

            I guess it comes down to businesses needing to justify expenses and consider opportunity costs (not just the cost of solar panels vs nothing, but what the return would be if they took that money and invested in some other area vs cost of solar panels).

            Residential customers are more likely to do it even if the payback isn’t clear, because it sounds pretty good, they want to do it, and they have the money.

            • absGeekNZ@lemmy.nz
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              3 months ago

              Yep, solar on residential doesn’t make much sense unless you can load match your generation.

              If you have people home during the day and run your aircon anyway. Maybe heat your hot water during the sunniest period. Maybe charge your electric car (if you have one at home).

              If the regulations change to incentivize feed in to the grid, this can make it make sense, but it needs to be at least 80% of what you pay per unit; there are grid matching solar inverters that will do the matching for you.

              • TagMeInSkipIGotThis@lemmy.nz
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                3 months ago

                Just to jump in here, residential solar makes a lot of sense for natural disaster resiliency. Your system would need to be sized to cover your bases in winter, but NZers should expect to experience days without power in a future where more Cyclone Gabrielle’s will occur. That’s why adding battery storage is a key part of it too.

                • absGeekNZ@lemmy.nz
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                  3 months ago

                  This is a good point, but for disaster resistance, you need to be able to run your fridge/freezer and charge your phone and radio.

                  A fire place for heating is a good bet. If you can afford it, a system sized to run your air con also would be great.

              • Dave@lemmy.nzM
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                3 months ago

                Battery storage for residential solar is getting popular, though this of course comes with additional cost that you then need to offset.

                I’d like solar, and I don’t really care if it has good payback so long as it’s roughly break even. I’m part of the problem 😆

                • absGeekNZ@lemmy.nz
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                  3 months ago

                  I understand.

                  If the feed in rate was ok, then it would be a good idea. But then again, if the power price keeps increasing, the solar + storage option starts looking good.

                  • Dave@lemmy.nzM
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                    3 months ago

                    Residential solar may also have another benefit over commercial. If the money wasn’t spent on solar, it would probably be reallocated to the mortgage. But by allowing you to borrow money for solar at 1% and put the rest of the cash into the main mortgage at 7%, you get 6/7ths of the altetnate plan.

                    The 1% is only three years then it rolls onto a normal mortgage rate, but that’s a big difference compared to companies whose borrowing cost is likely higher than the residential mortgage rate.

                    So residential solar is currently incentivised and commercial by comparison makes a lot less sense. So I guess this is where the govt could step in with subsidies or guarantees to reduce the cost to companies.