Andy Parkins

Embedded/UNIX/Android software engineer; guitar obsessed incompetent

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[Andy Parkins @andy_parkins]

@janrosenow @CarbonBrief Doesn't pass back of envelope test.

SCOP of 3-4 typical. Electricity 4-5x as expensive.

Even in the rare super efficient cases that do save money, the payback time on the capital invested is longer than their lifetime.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Should have been easy to show then. But I still haven't seen any figures from you that supported that.

I got 2% on your figures. That's an enormous hole to fill to get to 10%. If I'm a factor of 5 out, it should be easy to show where.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Let's say a generous 25 year life.

ROI of 9.71% is 0.37% p.a.

You're better of with a crappy cash ISA than a heat pump.

Even if it were 9% p.a., I can't imagine that's sufficient for the average person given the capital they must supply.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop I'm sorry, I'm done. I've tried my best.

I've looked at the data you pointed me to. When I show a rubbish time to break even you just tell me I'm looking at the wrong data and don't actually say what's wrong in my argument.

If the case were strong it wouldn't need tap dancing.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Oh come on.

There's a standing charge for electricity too.

But even if there weren't, £9 a month is not gonna pay off the investment. That's absolutely negligible on the scale of numbers we're discussing.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Hot water is not the significant energy user for heat though. A well insulated hot water tank will hold its temperature for easily half a day, more if you're willing to put up with the slightly lower operating temperatures heat pumps imply.

It's a small percentage over a year.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Okay.

Is this the data you want me to use? COP 3.6. About half a year. About half the kWh I used.

I don't really see any significant difference that would alter what I said above for ROI. Am I not interpreting this correctly?

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop But I should say... Happy to look at more data. All I did was use the numbers you supplied.

You pick whatever month you want that makes the case. I'll certainly be interested to look.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop Sorry to keep adding. But I do love data (thank you for supplying by the way).

Your gain from the battery is 2.9p/kWh of heat.

If we (unfairly) load all battery cost on heating, and using 13MWh per year, your battery gains you £377 a year. Or 13y break even (£5k assumed).

[Andy Parkins @andy_parkins]

@JillBelch They're obviously cheaper per unit. All the costs are capital costs, and come up front.

But then, since we don't pay the unit cost, we pay the CfD/RoC contract price, what does it matter what the unit cost is?

The lower the unit cost the more of the contract price is profit.

[Andy Parkins @andy_parkins]

@ManxRadio I don't really understand why this is a local issue. It should be national.

Even if you have never been to the tip, you benefit from its existence.

If I am in Ramsey, I benefit from the tip in Peel, because I do go to Peel sometimes and it's not covered in crap.

[Andy Parkins @andy_parkins]

@ManxRadio Isn't it politics 101 that you don't mess with the bins? You get voted out sharpish.

Aside from that, if the island is prioritising the environment, then you can't do better than avoiding incentivised fly tipping.

[Andy Parkins @andy_parkins]

@DiscussingFilm Entropy is the universe's equivalent of "death and taxes"

You can't unbreak an egg. You can't unbake a cake.

You can't undo a Kathleen Kennedy.

[Andy Parkins @andy_parkins]

@DaveThroup It's not growth if it's government spending.

[Andy Parkins @andy_parkins]

@James_BG Government tax revenue is about 50% of GDP.

If government bought beanie babies with it, the "beanie babies economy" would be booming. It then being the "only source of growth" would not be something to cheer.

Net zero is entirely government spending. It's not growth.

[Andy Parkins @andy_parkins]

@LeeHurstComic They're still trying to be ambiguous. By leaving "live" out on the first row.

You can watch itv and channel 4 on catch-up without a license. You just can't watch live.

[Andy Parkins @andy_parkins]

@KamilBaczkowicz @_heatgeek @skillbuilderuk @scop I don't assume anything. I'm using that as an example. You can extrapolate the maths however you like.

The point is this article is using the load shifting facility of batteries to make heat pumps "work". Which is not fair for modelling heat pump installs.