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tell me why this won't work - community generation

  • 29-09-2022 1:01pm
    Registered Users Posts: 575 ✭✭✭


    musing on the energy crisis for households and trying to come up with solutions, I had the following thought.

    What if you have a community, lets say a block of flats in Dublin, to keep things simple, and everything is powered by electricity. Heat, lights, water pumps, etc.

    those people can't fit solar, can't fit heat pumps, can't insulate their flat more.

    So lets just say they form a company, and buy a bit of land down the country with a grid connection. They then buy solar panels (+ batteries) and install them on the land. The solar panels generate sufficient electricity to match what is consumed in the block of flats. If all the residents are customers of the community electricity company and it has authorisation to sell electricity, would that work? What am I missing, apart from a load of cash to buy the land and panels.

    is there any technical or bureaucratic reason why this can't be done? I might be naive here. Educate me.



  • Registered Users Posts: 9,757 ✭✭✭antoinolachtnai

    Yes, could be done and makes a lot more engineering sense than rooftop panels.

    The customers wouldn’t all need to be in the one building.

    There is a structure provided for under the renewable energy directive to allow for this.

    There are some serious bureaucratic issues, in particular tax and metering.

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

    Solar panels are utterly uselss at this latitude. For four months of the year they generate next to nothing. Even over a full year they will only generate about 10-12% of the panels rating. Even if you were to carpet a few squre km of prime agricultural land with panels so that paltry 10% was equal to the entire energy use of the building, the batteries would cost as much as the apartment block or more, not to mention what the land and cabling would cost.

  • Registered Users Posts: 2,588 ✭✭✭Nermal

    The batteries would literally cost as much as the apartments they're powering.

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    ok, batteries are costly. Gotcha.

    I know solar isnt the most efficient at this latitude, but it is what it is. A wind turbine would be more costly and have years of objections.

    So, if we take 100 apartments, each using the average per annum, (12,000 kwh) thats 1.2Mwh. round it up and you have 1.5Mwh

    what does a plant runt to in cost these days, a bar a MW? So thats €1.5m plus install, connection, planning, licences, etc, etc.

    BUT! households using less in summer and more in winter when panels are producing more in summer and less in winter. So how to counter that and not waste excess?

    I thought batteries could help for load balancing, etc. but they may be expensive. Fair enough. Whats the other options?

  • Posts: 0 [Deleted User]

    Good luck persuading landlords representing 80% of the properties in any particular apartment complex to stump up cash on which they have no prospect of getting a return.

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  • Registered Users Posts: 2,153 ✭✭✭JMcL

    It's certainly doable and there's a lot of research going on into ways and means of bringing it about. There are a couple of main stumbling blocks: 1) regulatory inertia - nothing is going to happen without the CRU or equivalent saying so, and 2) It's really not in the interests of the suppliers for it to happen - why would they want me selling/giving excess energy to my neighbour when they can just take it as spill for free or as is now the case with at least some of them, a nominal sum?

    It's not entirely straightforward as there are issues over MEC (max export capacity) to think of, and ESB networks (i.e. the grid operator as opposed to the supplier) are going to be very cautious around that, though there are signs of progress on this front

    Some countries such as Switzerland are well down the road to enabling it, but you probably won't be surprised to hear that we're lagging somewhat

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

  • Registered Users Posts: 791 ✭✭✭CreadanLady

    Technically possible, but economically unviable. In the extreme.

    No-body would be interested in it anyway, unless you live in an apartment block full of solar nuts who are willing to break their holes financially for the sake of it.

    I think you underestimate the amount of work and cost involved. How will you finance it? Unless you have millions just sitting there, no lender will lend money for this sort of amatuer stuff.

    Are you really going to build/pay for an ESB networks substation at the point of interface to the grid? That alone could cost €250k plus.

    Planning permission, design, environmental reports, etc etc. None of that comes cheap.

    The MFV Creadan Lady is a mussel dredger from Dunmore East.

  • Registered Users Posts: 652 ✭✭✭eusap

    In eastern Europe you see a lot more District Heating, one central boiler providing hot water/heating to flat complexes and it seems to work well (gas is cheap) and i think they pay a fixed fee like water charges.

    But for electricity i guess this would be like setting up the old Group Water Schemes where a group of people come together to form a utility but in effect they would end up being another power company as they would need to sell there generated power to the grid and buy it back and resell to the residents and then you would need to meter each apartment and setup a billing system etc....

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  • Registered Users Posts: 6,157 ✭✭✭Ubbquittious

    They are selling to the grid and buying back from the grid at a much higher price so compared to installing your own panels it's a bit like filling your car with petrol but holding the nozzle a good bit back from the car so nearly half of it spills on the ground below. Except that what you spill on the ground automatically falls into the tank of some billionaire's superyacht.

    A better system would be if the whole block of flats was directly connected to said solar farm & battery and the entire building only drew from the grid when its batteries are depleted. They will prevent that system arising through bureaucracy because it would require 100% participation and everything that's registered as a house is entitled to have its own grid connection and MPRN. At the very least you'd have to have the wiring for both systems available in each apartment

  • Registered Users Posts: 2,232 ✭✭✭waterwelly

    How can they be utterly useless if they are producing for the other 8 months?

    Your 10%-12% of rating, I assume you are including hours of darkness to come up with that figure. I don't think even the most dimwitted in society believe solar panels work in the dark.

    Anybody with an EV is absolutely quids in in a big way when they have solar setup correctly.

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

    Abstract: Long-term monthly average daily solar radiation values on horizontal surfaces at 20 locations in Ireland were used to model the performance of a 1.72 kWp grid-connected PV system. Global solar radiation on horizontal surfaces varied between 865.1 and 1,127.9 kWh/m2/yr with a mean of 947.9 kWh/m2/yr. Annual energy yields varied between 869 and 1,156 960 kWh/kWp with a mean of 960 kWh/kWp. The capacity factor for the PV system varied between 9.9 and 13.2% while the mean was 11.0%

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

    Beacause you need power 24/7/365 and you need the most energy in winter. If a cloud blows over a solar panel, the output drops about 80% almost instantly. This is one of the cloudiest countries in Europe. In an entire year, only about 14.5% of all the hours in the year are of direct sunshine - 86% of the time it's either pitch darkness or cloudy. To make solar panels useful, you need an application that doesn't care when it gets power or batteries or some other energy storage, which are expensive.

  • Moderators, Home & Garden Moderators Posts: 5,467 Mod ✭✭✭✭graememk

    Yeah, do you even know what that means? Their numbers are coming in bang on what my prediction said.

    >>"Even over a full year they will only generate about 10-12% of the panels rating."

    Its the amount of global solar radiation that is converted to power.. It does not mean panels only produce 10% of their rated power. Panels are about 18-19% efficient in lab conditions.

    Playing about with JRC, the same panels in Spain will generate about 50% more power than in ireland, In the middle of the sahara, Its about 100% more. (and possibly less, due to de-rating because of temperature, once panels go above 25C they start generating less power)

    So yeah that numbers about correct. 10% of annual global solar radiation. Although the max is about 18-19%

  • Registered Users Posts: 6,157 ✭✭✭Ubbquittious

    Yea I don't get it. Mine are working grand and I think so are everyone else's?

  • Registered Users Posts: 1,355 ✭✭✭DC999

    1st off, any clean energy creation if a good thing in my mind. But can't break the bank or money is better elsewhere. So 1 doesn't need to compete with the other. More types are better. Solar for when sun is shining (based on light levels not temp), wind is good in winter when solar is low and at night.... hydro for 'burstable' peak times...

    The largest wind turbines in the world (as in newest ones) generate power for 1 house for a day in one turn (7 seconds). But the cost of those is massive and they are offshore with tens of them setup. It’s ~5 years from planning to the turbine spinning connected to the grid. UK impoverished housing estate has formed a co-op to setup their own on the land within the estate (large complex of flats afaik). And they got funding for it and being built.

    Our house solar (which 1 love) takes hours in summer to do that. Not seconds. But...the roof space is available and free and doesn’t take up farm land. Cost under 10k per house roughly. Could the State roll out solar to all houses it owns and it then gets paid for what they create? Solar can be live much faster that turbines (but it’s micro energy creation with a small m). Though is you have tens of thousands of micros….

    In terms of competing with usual space like farm land, some countries are adding floating solar ‘farms’ on lakes so doesn’t use the land. Costs more (as they need to be on a floating surface and maintenance costs would be higher), but land is free as the state owns it. Other countries are trying strips of solar panels in the middle of farm land - so doesn’t impact the growing. Farmer then gets 2 incomes. 

    UK has less farm solar space used than the land used by golf clubs. Do we ban golf clubs as they take up farm land? I'm being a bit ridiculous of course.

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    See, I have a plan for that as well. 70% funding for plant from finance house. Balance from private investors. Repayments from bills to residents. 7-10 year repayment schedule. Plant lasts 25 years. Profits repaid to shareholders (residents)

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

    Capacity factor, in terms of solar panels, is the ratio of actual annual energy output to the theoretical maximum, which is defined in the panels rating.

    And that theoretical maximum is the total hours in a year, not the total daylight hours.

    The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period.[1] The theoretical maximum energy output of a given installation is defined as that due to its continuous operation at full nameplate capacity over the relevant period.

    Here's the capacity factors for some solar installations in Scotland:

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    I think you underestimate the amount of work and cost involved. How will you finance it? Unless you have millions just sitting there, no lender will lend money for this sort of amatuer stuff.

    Are you really going to build/pay for an ESB networks substation at the point of interface to the grid? That alone could cost €250k plus.

    Planning permission, design, environmental reports, etc etc. None of that comes cheap.

    ok, this is where it could/would fall down.

    Financing can be done. There are outfits who will fund solar plant up to 70% (although they may want a PPA agreement with a better covenant than a bunch of apartment residents) and balance from private investors with a hefty rate of return.

    the grid connection could be a problem alright. I hear ESB take forever with them, is that right? Planning, design, environmental impact reports will all have to be paid for alright.

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  • Registered Users Posts: 2,232 ✭✭✭waterwelly

    The feed in tariff helps a lot there. As does an EV battery or a battery as part of your PV setup.

    Combine PV, EV, batteries and night rate electricity and you are really onto something sweet.

    Panels are useful, I don't have them, yet, you seem to be on your own claming they are"utterly useless" in Ireland.

    But sure you are right and we are all wrong.

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    But if their energy provider is actually producing some of the electricity, then it is an offset, no? Or is it because teh offtake is remote from the feed in that there's a buy and sell of energy?

    yeah it would be ideal to have the solar on site, but having the block of flats directly connected to said solar farm isn't feasible. Same for most apartment dwellers in cities.

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    yeah, thats kind of what i was thinking alright. There's one of those in Ireland, must dig out some info about it.

    Bob is a good skin. Does a lot of EV reviews.

  • Registered Users Posts: 6,157 ✭✭✭Ubbquittious

    Yea if said company became a licensed MPRN-acceptor it would probably get a favourable deal. But then you have the likes of Community Power charging an eyewatering 77c per kwh ( Community power seem like a wholesome crowd so I suspect the game is rigged against them in some way due to their diminutive size

    I have experienced the same when I worked for a 'switchless' broadband reseller, somehow the wholesale price they were offered was worse than what the likes of Vodafone were selling directly to the consumer for

  • Registered Users Posts: 2,232 ✭✭✭waterwelly

    Why are you benchmarking against something which is irrelevant, like including hours of darkness, early and late in the day etc., which everybody discounts as unproductive time anyway.

    Somebody posted their bill the other day, it had something about units consumed versus the same period 12 months ago.

    I suggest you go look for it, clearly PV is far from "utterly useless" which is your claim.

  • Registered Users Posts: 19,415 ✭✭✭✭cnocbui

    I think people are getting a bit confused here; You can use taxes and subsidies and tarrifs to make people think that almost anything is a great idea and the best thing since sliced bread.

    I have been purely talking about the technical realities of solar, not the government distorted financial proposition offered to early adopters.

    Just look at diesel vs petrol. Gormly and his idiot Green party and his idiot coalition partners made diesels look like the best thing since sliced bread to your average Irish person. That doesn't mean diesel is really cheaper than petrol, or better, it just means the government used financial distortions and incentives to make it appear so. Now diesel enthusiasts can happily breath carcinogens all day long while thinking how financially smart they are. Way to go...

    Petrol would normally be significantly cheaper than diesel because when you refine a barrel of oil, you get a lot more petrol from it than diesel.

  • Registered Users Posts: 6,157 ✭✭✭Ubbquittious

    Right now they are subsidising gas-generated grid power to the tune of 600e per user. Good few people here put in solar with no grant and it's paying off for them

  • Registered Users Posts: 575 ✭✭✭TheWonderLlama

    Gotcha, yeah, I guess this is the barrier to entry the main players have to keep the small guys out. The wholesale price is high at the bottom end, but lower the more you buy. Preferring large buyers.

  • Registered Users Posts: 442 ✭✭Kurooi

    You don't just put down solar panels and leave them be. They will require constant security, maintenance, insurance. So now you're looking at running costs. You will charge them to the residents, right? And from time to time that won't cover it, say 5 years from now you can reasonably expect to add some panels, replace existing ones and that will be a big spend. No way in hell will any of these residents agree to pay when you come over with one big bill, they can just switch to a regular provider. So you should charge them over time in advance, a little rainy day fund on top of the running costs you're incurring.

    You just invented bills. And you're running a regular company. Back to square one.

    All that said, I understand where the idea is coming from. It makes no sense to me at all that currently I see regular people putting up tiny solar panels on their rooftops. They will often face the wrong way (because the person doesn't have a south facing roof) or be shaded, the panels would be substantialy better and cheaper if they were bought in bulk. It makes no sense they pay for individual batteries, installation and wiring up their house to produce utilities. It's so uncoordinated.

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  • Registered Users Posts: 791 ✭✭✭CreadanLady

    That is why we have the likes of ESB networks. To run a grid so you don't have to.

    The MFV Creadan Lady is a mussel dredger from Dunmore East.