Random Renewables Thread

I think it's a lot more of a runner these days than it was in yesteryear. Can't remember the thread it was in , but someone posted there recently (within the last week) asking for advice on 420-430w panel there for €57 each.

Jeez, I remember paying double that and then some for a 365w panel 2 years ago. At those kind of prices for panels nowadays things which weren't that feasible even a few short years ago are suddenly much more viable.

With panels so cheap - even north facing will recoup your outlay quickly enough. To be fair now, you won't get much production out of them in winter, but they will pay for themselves.

True - though many people in the past skipped installing panels on north roofs as it simply wasn't worth it. I'm lucky enough to have East / West (and south on my shed), and I'd have thought twice about it myself a few years back. Nowadays I'd be plastering all and sundry. :-)

Agreed with you about the NC6 restrictions….still some inverters even go to 100% over provisioning. (got to watch the string voltage though that's probably the determining factor for most now)

Great re-use of legacy Cold War underground oil storage in Sweden to store heat for a district heating system.

The window squidgy came in handy to remove snow from the ground mounted panels. Even with the freeze tonight the array should be fine to produce power tomorrow.

The array on the roof is a different story. They are unlikely to produce anything until Thursday or Friday. Currently an inch or two of snow sitting on them which will freeze shortly if it hasn't already.

From a fire hazard point of view I don't know if I'd be happy having something like that from AliExpress anywhere near my house.

+1 on that. You'd spend more on the cheap electric pads than you would ever save over the life of the panels. Best thing you could do if you really wanted to, was once you were sure that there wasn't an addition freeze coming, get out the hose and if you have enough water pressure to reach the roof - just spray the snow off the panel with cold water. Even cold water at 2-3 degrees will melt off the snow.

What's the best thread to ask a general Heat Pump question? Please move if not here.

We've a B3 1970s 3-bed semi-d. 90sqm, gas boiler, normal rads, MHRV, decent windows.

The gas boiler is working ok and I can't see any reason to change to a heat pump but am wondering if I'm missing something?

We're reasonably environmentally conscious, have had solar thermal and MHRV for 15 years, but I can't see a heat pump being better for global warming in our case, at least for the next 5 years. Only 35% of Ireland's electricity comes from renewables and it will be at least another 5 years before a sufficient amount of offshore wind becomes available to change that. Considering the distribution losses of electricity, is there much environmental benefit of a 65% gas powered HP versus a 92% efficient condensing boiler?

Our gas Heating costs last year were €1300 for 9,000kWh. What would a realistic cost be for running a heat pump? €600 ? So a saving of €700 per year versus the heatpump installation cost. I've seen €16k quotes here. So a 22 year payback and the expected lifetime of a heatpump?

I expect our rads will need to be replaced with larger rads and the pipework upsized. Which will mean walls and ceilings replastered. Hot water cylinder is a Kingspan Albion solar coil cylinder, so could that be reused? Or do we lose the solar thermal if we do reuse?

You're committing the eco fan boy error of overly optimistic eco efficiencies to support your case. Think more like 3.5kw of electricity at your point of consumption per 10kw of oil/coal/gas, at various power plants. A real world COP of 3 is only achievable when its mildly cold and you can warm an A+ rated house with a modest 30-40° flow. Push the heatpump in cold weather and your cop drops as you heat the flow with more and more consumed electricity. Some HP manufacturers show these figures in their specs, with plenty of 1.5 and less COP stats after modest increase in demand.

Spend your ten grand on better insulation, put 50mm boards on the inside of external walls, maybe triple or thermal glaze the windows, and enjoy your 95% efficient gas boiler until there's some honesty in the eco alternatives. There's feck all solar or wind these last few freezing nights, and those with HPs and no electricity will freeze to death as they've no fireplace either. Their EV battery is flat too.

Why would the Ev battery be flat? You do realise you can go to a public chargepoint too?

Why would it be flat? I’ve two EV’s of older vintage in the driveway, nowhere near as good as current generation of purpose-built EV platforms, and neither is flat.

In that case their diesel car must also be empty.

And the local filling station cannot use their electric fuel pumps either.

The misinformation and FUD is strong here!

Funny that, my Ev hasn't needed a charge in over a week, just over 200km driven. My genny can run the heat pump and charge my 26kwh storage battery. Nice to be able to switch the genny off at night. Power was out today and we didn't even notice as the batteries took over, but carry on 🫡

What are the best value rack mount 48v batteries to buy at this time? Thinking of building a partially off the grid system for the summer

Bingo time