Random Renewables Thread

Don't forget about the disconnect at the end-user level where they are left with these devices and little or no understanding around how to optimise the units. Look at the historical questions on here as examples. The jump from gas/oil/electric isn't a 'straight conversion' for the simple customer as they don't understand how to manage the COP and the multitude of factors which influence it on a day-to-day basis.

Plus as many of us come from a past where heating was mainly demand-based and hence there was some reasonable control over the cost, moving to having an always-on heating system in a poorly executed retrofit was always going to cause some problems, especially if the focus of the refit was on insulation and no element of airtightness.

In the UK they have the likes of HeatGeek who are serving to educate both the installers and end-users, but we don't appear to have the equivalent promoters/educators here yet.

Out of interest do you care to identify as to which segment of the industry you work in?

It seems people are watching a bit too much targeted Youtube... All middle ages men, same target audience

The article states the core problem is undersizing, something I pointed out a few posts back. Installing a HP which has say a max mains consumption of 5kw, on the understanding that it has a cop of 3.5 and will supply 17.5 kw of heat, only to find the cop refers to much lower input and output, maybe 3kw in will give 10.5 out in ideal conditions, but less as the flow heats up. This lower output will be very slow to heat a cold house from the off, so the heatpump moves into its inefficient part of its transfer curve. Worse, it invokes a straight heating element as described in the article, no cop there. 3kw in, 3kw out. A much larger hp will stay in its sweet spot and allow for high outout burst demand, but such a beast is enormous, expensive, and capable of bankrupting you if it too goes into inefficient mode for the variety of reasons mentioned.

I personally think heatpumps should only be a hybrid addition to a standard heating system, a small 2.5kw system running only ever at low temperature and modest Cop would offset quite a lot of fossil usage. I posted such an innovative Dutch model back in this thread, ideal for older and difficult to retrofit houses. Ordinary houses in other words.

you appear to not understand how heatpumps work, so you want people to oversize them just so they can use it like a gas boiler? There's no need for high burst demand if you are using it properly

it turns out that heat pumps trigger the same reactions as evs…

I'd agree a heatpump without the correct upgrades to insulation and rad sizes etc is folly, is there a suggestion somewhere that it isn't and you should just plop a heatpump into a d rated house?

I suspect several of the houses with bad heat pump installations probably got some new windows and attic insulation and that was it as far as upgrades go

There were probably several very optimistic figures put in for the existing insulation and air tightness which didn't account for aging or mistakes during construction

I would have to pay ESB 2,000 whole quids just to get the import capacity for a heat pump. Then I'd have to get a new fuse board. For now I think I'll just stick to praying that the auld kerosene boiler won't pack up

12kVA MIC ⇒ 336kWh per day or 123MWh per year. Average Irish house uses just 3MWh per year. A heat pump and a couple of EVs in an electric only home would make the house use maybe 15-25MWh per year, so more than plenty

The main problem with a 12kVA connection is that you can't charge / run everything at the same time

I'd guess most houses should be able to run a heat pump without upgrading the import capacity. That said if "everyone" was to get a heat pump (say within a decade) not sure where all that power would come from. Course if you have an EV charging, a 9Kw electric shower, etc all running off your 65A supply…….yeah I can see "trouble at mill". :-)

What's your typical heat pump consume per day…20-30Kwhr/day or something? If a million homes migrated to HP's over the next decade or so, that's a lot of power gonna be needed!

A lot of wind farms are in the works, unfortunately nimbyism and general thickness are delaying some of these projects or knocking them on the head completely. Only in the past week an board pleanala - rightly or wrongly - put stop to two separate wind farm developments.

A lot if that is looking for go away money, like that disgusting obese lardarse in Galway with his fake environmental watchdog companies, seeking judicial reviews on everything.

that usage is for maybe 30 percent of the year, during the summer it's a few kwh per day

EVs will do wonders for stabilising the grid as they are predominantly charged up at night when we often have too much renewable electricity.

This will get even better when V2G becomes possible, then they can be used as "peaker plants" doing us all a big favour, saving the government from spending a fortune on grid batteries and interconnectors and making the owners some serious money. The holy grail. For me this development was all going far too slow, so I have installed a large home battery, 80kWh. Not cheap of course, but I expect to be well rewarded for it.