Random Renewables Thread

Me praying for pinergy not to change anything 😂

I didn't say a 15kWh battery costs €1000

You can get the 16 * EVE 300Ah or so cells for €60 each or so plus VAT and a reasonable amount for shipping. They include busbars and bolts / nuts. Add a few cables to that and a JK BMS with active balancing and CAN comms (so it can talk to your inverter), a fuse / breaker and you have a high quality 15kWh pack for less than an installer would charge you to install a lower quality 5kWh pack

Are you saying that's you can't get a 15kw for that money? Not sure what you meant above. But you can grab 16x 305Ah cells for €1,150 (incl vat) from NKON. Grab a BMS and a few do-da's and your probably coming in shy of €1500.

You'd still need a way in charging it (ME3000 etc or some other equivalent), but yeah under €2k I reckon and you could have yourself a 15Kwh battery.

Granted to be fair, this isn't for everyone. Old misses Noggins down the road isn't going to have one unless she happens to be handy with a soldering iron and a multi-meter :-) …. so it's not shall we say "general consumer friendly" but the math works.

Hey, a bit less of the Mrs Noggins insulting! She was handy with the soldering iron when most of us in here weren't even born yet 😁

you don't use a heat pump like a boiler

But there you can opt in to flexible rates. Which is extremely lucrative if you have the right setup. Almost always on sunny days around the noon hours, the price of electricity is negative. So you load up all your cars, your battery and use as much electricity as you can, and they pay you. And of course just switch off the DC input to your inverters

what?

Like anything new you need to educate yourself on how it works. It doesn't work like a boiler so only an idiot would use it like one!

Over a year a properly set up h/p system will heat a house for a lot less than an oil based set up.

ah but your house is at a comfortable 21 degrees all day ( or part of it, bedrooms don't need to be).

I'm in a situation where the house was built with the heatpump as the heating solution but I know it's a lot cheaper to run than my parents oil fired system and anyone I know with a gas boiler and similar sized house, again I shift some heating and all hot water to night rates.

Anyway the point was comparing a specific use case which it's not designed for against a gas boiler is a bit silly.

Ah for sure it makes sense for any newly built, well insulated house to have A2W with underfloor heating on all floors and no radiators. We should stop burning fossil fuels ASAP anyway!

Your previous posts did not reflect your education though. You thought a 9kW heat pump would use 8 or 9kW. When a boardsie confirmed his heat pump of a similar size only uses 1.6kW and is on a 20A beaker you shifted the goalposts to say COP is fake.

"People" would be sitting in a cold house during the day and then use the boost function with a heat pump. Arguably that is condescending, even calling people idiots in a roundabout way because they couldn't possibly change their habits.

If you read the technical specifications of heatpumps, and I've read a good few, you'll see that as you try to extract higher flow temperature from the unit, in order to perhaps heat your home in the same actual hour you request it, you'll find that cop diminishes rapidly, to fractional figures. Hardly surprising as you're trying to extract heat in Joules from a volume of cold air that would require cooling that air to sub freezing temperatures, eventually icing up the evaporator. If your heatpump is consuming 9kw, and is churning to try and produce unobtainable heat, then a cop of 1.2 to1.3 would not be uncommon, . You may well have little over 10kwh of heat to the flow after losses (there are always losses, especially from those huge fans), so to all intents and purposes you are heating your home at peak electricity rates. Theres no getting away from this, you'll need a bigger heatpump with a higher transfer rate of cooler flow to ufh or full wall height radiators to transfer the volume of heat energy required at such low flow temperatures. It's how it works. It's physics. This blind statement that a 9kw heatpump produce 27kw of heat unconditionally is irresponsible, but is perpetrated on all the eco media sources.

A modest size heat pump will happily extract twice or more than the heat energy of it's electrical consumption on a nice day like today, a COP of 3+ is no problem. But who needs its on a warm day? There is way to much factual reporting of heatpump nightmares to ignore the issues. Extreme Insulation, vast radiators or UFH, and a properly sized unit might give you a reasonable chance of 24hr comfort, but then you're already on the way to a passive house. There are plenty of BER box ticked A rated homes with straight out 6" vents in every room. Your tepid heatpump flow has no chance in those circumstances, as air temperature will never increase to comfort levels, so you'll have warm UFH feet, a cold arse Nd a large electricity bill.

Modnote: this has been copy/pasted from this article https://archive.is/14fax

(Thanks @deezell )

Domestic heat pumps cost from €7,000-€15,000 each, excluding installation, but there has been a litany of problems. The issues include what one industry expert tells me is an under-sizing of heat pumps in properties.

While the heat pump technically meets the building regulations, this is only achieved by frequently using the back-up electric immersion heater, which defeats the purpose and lands the occupier with huge electricity bills.

Heat pumps have been standard equipment throughout Europe for 50 years, so there should be no reason for persistent problems here. With new technology, teething problems are inevitable, and particularly if there is insufficient training and experience in the industry.

However, we are now a decade into the mass installation of heat pumps and problems should not be recurring on a large scale.
The biggest complaint being flagged to me by engineers, apart from the under-sizing issue above, is incorrect installation, followed by incorrect commissioning of the systems.

Further problems can arise in the “localisation” of foreign manufactured heat pumps to meet Irish regulations, for example, the addition of external controls and timers.

A problem is that the default solution, which allows people to keep living in the property, is to override the system by switching it to the immersion setting. As the row over culpability rumbles on, many owners are probably not even aware that they are heating their radiators via their immersion – at enormous cost.

What has been your experience of your heat pump?