Assume that TWG stores collectively use 500MWh/yr, as long as Lodestone feeds more than 500MWh/yr into the grid, the power is offset. I hope they account for transmission losses, as the solar installation is not on TWG stores but in some other location. So maybe rather than 500MWh Lodestone will need to feed in 550MWh.

[–] themusicman 1 points 10 months ago

If there are non-TWG power consumers near the farm and other power producers nearer TWG, transmission loss is irrelevant - power is power

[–] [email protected] 5 points 1 year ago (2 children)

Interesting that it's far cheaper to have the farms in remote locations rather than on the actual buildings, especially since the nature of the buildings the warehouse group occupies would make it relatively easy to install solar.

[–] [email protected] 6 points 1 year ago (1 children)

I thought that was interesting also. Which is why I mentioned that I hope they are accounting for transmission losses.

I would have assumed that large warehouse type buildings are the exact type where rooftop solar makes a lot of sense. We are looking at it where I work.

[–] [email protected] 3 points 1 year ago

The other issue I thought about after making that comment, is how many of it's sites does TWG actually own? I imagine putting solar on someone else's building could be problematic.

[–] [email protected] 2 points 1 year ago (1 children)

Stupid question: why dont they use at least some transparent panels on top of the buildings to let in light during the daytime? Right now i'm seeing huge, dark halls who are illuminated by rows and rows of artificial light (probably making up a large portion of their power bill), while the sun is providing free, natural light outside most of the business hours.

[–] [email protected] 1 points 1 year ago

Quite a few large buildings will do that, every third or fourth roof piece will be transparent to act as a skylight. I don't know why some don't do it, perhaps the transparent pieces don't last as long?

[–] [email protected] 5 points 1 year ago (3 children)

Just checking I understand this right, a solar farm company and The Warehouse are working together to make the solar farms produce as much electricity as all the stores use?

Didn't some power company get in trouble recently for telling customers they were using green energy, when it's not actually possible to distinguish where electricity comes from in the national grid?

[–] Floofah 4 points 1 year ago (3 children)

I guess if the stores only ever use the same amount of energy that they feed to the system, then they can say they are 100% self sufficient in electric. Of course after dark they need a different source, but if they’d already fed that extra night time requirement into the system during daylight hours, then does the self sufficiency determination still apply?

[–] [email protected] 4 points 1 year ago (1 children)

Another big thing here - do these solar farms already exist or are they already planned? Does The Warehouse claiming to use solar actually increase the amount of solar in the grid, or is it just greenwashing?

[–] [email protected] 2 points 1 year ago

Oh it's totally green washing.

But, there might be some actual extra solar generation being funded, but that'll be a happy coincidence.

[–] [email protected] 2 points 1 year ago

They wouldn't be considered entirely solar powered unless they also had some mechanism to store that energy during the day, and release it into the grid at the same rate the customer is using it.

But, that's why we have a diverse range of energy sources in NZ.

[–] RegalPotoo 2 points 1 year ago

Except the grid can't store energy like that - if you generate twice the energy you consume, then someone else uses that energy and the base load generators slow down ever so slightly to accommodate. When it's dark and you need that energy back, something else has to generate the power for you.

Net metering is a book keeping device, not actually how power generation works.

[–] [email protected] 2 points 1 year ago (1 children)

I don't really see the difference myself, especially considering we only have one national grid, and this is how all our other generators and retailers operate.

[–] RegalPotoo 2 points 1 year ago (1 children)

The issue with it is that the grid has to consume the energy in the same instant that it is generated.

Picking some easy numbers to make the example clearer; say my store uses 24 units of electricity per day - 1 unit per hour - and say there are 12 hours of useful sunlight per day. I can install enough solar panels to generate 2 units per hour of sunlight, generate 24 units in a day, and be "100% renewable". Except in reality it's hard to actually be using 100% renewables, because for the 12 hours per day when my panels aren't doing anything I still need power, and that power has to come from somewhere.

Electrons are fungible - power generated by solar is just as usable as power generated by burning gas - but generation capacity isnt. A kWh of stable renewable capacity that can reduce the demand on a non-renewable generator is much more "green" than a kWh from a renewable source that can only generate when capacity is already high - you'd need to keep the non-renewable generator around to pick up the slack when the capacity drops.

The situation in NZ isn't as bad as it could be because we get a lot of our energy from hydro, but there is still the problem that solar generation isn't constant, and the times of the day where it peaks don't line up with the times of the day where demand is highest. This is going to get worse over the next ~20 years as more people switch to EVs that they'll want to charge at home overnight. Systems like grid-scale batteries and other storage technologies might mitigate this, but they are a lot less cost effective than solar panels kWh for kWh, so projects like this tend not to include them

[–] [email protected] 1 points 1 year ago

The EV thing is another reason why I think we need to get solar on the roofs of office buildings rather than houses.

We're quite fortunate to have a strong hydro base in NZ, because it can be ramped up and down very quickly to fill in the gaps left by renewables, and in some cases even store energy, although I don't think we have much pumped hydro here yet.

[–] [email protected] 1 points 1 year ago (1 children)

This issue really irks me. It's like the Dutch(?) trains that are run 'completely on solar power' when in reality, they just use the equivalent amount of solar power. Using this logic you can just separately assign factories etc with equivalent power usage and say they are 'completely run on solar power' without referencing the other blocks, and voila, suddenly everything is green and run on a single solar panel. Dishonest accounting.

[–] [email protected] 3 points 1 year ago (1 children)

completely on solar power' when in reality, they just use the equivalent amount of solar power.

I don't see the difference myself.

[–] [email protected] 1 points 1 year ago (1 children)

In this case, it looks like TWG is actually contributing to new solar installations. However, the difference to me is like this:

NZ generates around 80% of it's power from renewable resources. So a wind farm could just sell the right to say Countdown to say that the power generated there is for Countdown. Nothing changed, no new renewable generation was created, no one built a wind farm for Countdown. They simply painted their logo on the side and said now we are powered by renewable energy, with exacly zero environmental improvement over the state before.

If TWG are actually funding new solar farms then that's a bit different, it at least has a real world impact.

[–] [email protected] 2 points 1 year ago (1 children)

In the Countdown example, they'd have to make sure their power use was matched by what the generator was putting in, in which case they can accurately claim they sold the power to countdown. They may well be paying significantly more per MWH than someone buying coal or gas generated power at the same time.

While it may seem bizarre, it's how our energy grid and market works.

[–] [email protected] 1 points 1 year ago (1 children)

It's a made up example. but yeah, plenty of places claim to be powered by this or that and I doubt they are counting the timing of it in their claim.

[–] [email protected] 2 points 1 year ago (1 children)

I'd be shocked if they weren't myself.

[–] [email protected] 1 points 1 year ago

I wonder if we'll ever know.