Green, ethical, energy issues in the news

Spies

Geothermal energy seems sensible if practical to do so. 

https://www.independent.co.uk/tech/geothermal-energy-renewables-quaise-hole-b2036201.html?amp

Solarchaser

As has been discussed a few times already if RE is overbuilt and the batteries are filled, then that's the perfect time for H2 production as it can be stored to cover the much talked about 2 weeks of grey days without wind, the cost will largely be irrelevant as it would be excess re that would otherwise simply be curtailed. 

But H2 isn't a direct replacement for gas in homes, so doesn't solve that issue even if we imagined its in plentiful supply eventually.

As someone on octopus go faster, I've had my rates guaranteed for another 11 months, which is great, however the gas price which is not fixed has now more than doubled. 
This puts me in the strange position of having gas which is significantly more expensive than electricity during the go faster period.
A great problem to have, but it also highlights a problem of the proposed gasless future.

My combi (soon to be ripped out) is a 28kw unit, but my electric supply (brand new as of 2 weeks ago) is only 25kw

And so even if there was cost parity, or in fact no gas, I cannot simply use electricity to displace gas like for like.

In the darkest /coldest months I'm using over 50kwh of gas per day and mine is not a huge house, and is well insulated.
I have friends who use triple this on a new build.

Heat pumps will help, sure, but they don't work in every scenario. 

My thoughts are a thermal store which I heat during the go faster period, however to use as central heating, the temperature has to be above 60c really, so how do I store 50kwh of 60c+ hot water, that's going to be a huge water tank.... probably too large for a loft installation.

No how much power do I use to heat that water... 18kw? So then I have 7kw left to charge my ev, ok... but what if I still have an electric shower, or white goods are on in the house?

I'm confident I can make it work FOR ME, but that in no way means it will work for the majority if people.

There are still many problems to be solved before we can really move away from Fossil fuels. 

QrizB

Solarchaser said:

As someone on octopus go faster, I've had my rates guaranteed for another 11 months, which is great, however the gas price which is not fixed has now more than doubled. 
This puts me in the strange position of having gas which is significantly more expensive than electricity during the go faster period.

I'll be in the same position come April. As discussed elsethread I'm all set to start heating water electrically.

My combi (soon to be ripped out) is a 28kw unit, but my electric supply (brand new as of 2 weeks ago) is only 25kw

And so even if there was cost parity, or in fact no gas, I cannot simply use electricity to displace gas like for like.

In practice, you probably can. Your house is unlikely to need 28kW of heat, more likely a max of 10-15kW (you can check this by adding up the ratings of all your radiators). The combi will only get close to 28kW when supplying instantaneous hot water to eg. fill a bath. If you revert to stored hot water you're likely to have enough capacity in a 100A supply.

In the darkest /coldest months I'm using over 50kwh of gas per day and mine is not a huge house, and is well insulated.
I have friends who use triple this on a new build.

That's evidence there; if your highest winter use is 50kWh/day, that's an average of 2kW, or say 4kW if you only heat your house half the day. Your friends might need 12kW.

Heat pumps will help, sure, but they don't work in every scenario.

Which scenarios don't they work in, and do any of these apply to your home?

My thoughts are a thermal store which I heat during the go faster period, however to use as central heating, the temperature has to be above 60c really, so how do I store 50kwh of 60c+ hot water, that's going to be a huge water tank.... probably too large for a loft installation.

What you're thinking of is one (or two) of these. They claim to store 40kWh in a box the size of a washing machine.

Coastalwatch

Hi SC, similar to yourself we had a 30kW combi which in the dark winter months saw it devour 50kWh's gas/day. This has since been dispensed with and replaced by two 2kW a2ashps for space heating and a 210 litre thermal store heated by a 3kW element supplied by off peak leccy in winter and generally solar between the spring and autumn equinox. Admittedly the heat pumps run approx 18 hours day in the darkest months but they've keep us very comfortable temperature wise for the last two winters so have no plans for going back to FF's anytime soon.

Admittedly, for all I know our boiler may have been overspec'd, we live in a two bed bungalow of circa 100 sq metres floor area, but believe that the high output was required to satisfy DHW on demand as opposed to being gently heating up in an immersion or thermal store whereby half that 30kW figure energy wise may possibly have been adequate. But I'm no heating engineer so just my take on matters.

From our experience over the last couple of winters, then in our case a 25kW supply has been perfectly adequate accepting that we live in balmy Suffolk as opposed to the fiercer winter climate t'up north.

Solarchaser

QrizB said:

Solarchaser said:

As someone on octopus go faster, I've had my rates guaranteed for another 11 months, which is great, however the gas price which is not fixed has now more than doubled. 
This puts me in the strange position of having gas which is significantly more expensive than electricity during the go faster period.

I'll be in the same position come April. As discussed elsethread I'm all set to start heating water electrically.

My combi (soon to be ripped out) is a 28kw unit, but my electric supply (brand new as of 2 weeks ago) is only 25kw

And so even if there was cost parity, or in fact no gas, I cannot simply use electricity to displace gas like for like.

In practice, you probably can. Your house is unlikely to need 28kW of heat, more likely a max of 10-15kW (you can check this by adding up the ratings of all your radiators). The combi will only get close to 28kW when supplying instantaneous hot water to eg. fill a bath. If you revert to stored hot water you're likely to have enough capacity in a 100A supply.

In the darkest /coldest months I'm using over 50kwh of gas per day and mine is not a huge house, and is well insulated.
I have friends who use triple this on a new build.

That's evidence there; if your highest winter use is 50kWh/day, that's an average of 2kW, or say 4kW if you only heat your house half the day. Your friends might need 12kW.

Heat pumps will help, sure, but they don't work in every scenario.

Which scenarios don't they work in, and do any of these apply to your home?

My thoughts are a thermal store which I heat during the go faster period, however to use as central heating, the temperature has to be above 60c really, so how do I store 50kwh of 60c+ hot water, that's going to be a huge water tank.... probably too large for a loft installation.

What you're thinking of is one (or two) of these. They claim to store 40kWh in a box the size of a washing machine.

I think you picked up on some of my post, but missed others.
Regarding the boiler, as I said, I can't replace the gas with electric LIKE FOR LIKE due to the current draw involved.

I think you perhaps missed the bit about having a lower electric cost for only 3 hours, so heating with electric at 2kw/ hour a. Wouldn't work as you wouldn't heat the house when everyone is in bed, nor when everyone is out at work.
If I did that, my heating requirements would be much higher.
Heating the half time at 4kw/hour while paying 15/30ppkw would bring an eye watering bill which would be the equivalent of wiping out all of the solar, batteries and insulation I've done over the past years, this is not a practical solution.

I am trying to at least be cost competitive while ditching the gas.

Heat pumps will not work for me as they require the house to have a good seal, my wife likes open windows (yes, even in the dead of winter) and will happily talk to someone at the open front door for an hour, and when back in will cosy up to the radiator because the house now feels cold 🤷‍♂️
My children have a cat which they like to call on, then leave the back door swinging open for infinity until the cat comes in.
So a heat pump will not work for me.

Perhaps the other part to state here is I have a young family, and a wife who likes things a certain way, solar optimisation was causing friction, this gave me a legitimate route to batteries, which has definitely helped marital harmony.
Having broached the subject of heat pumps.... well I won't use the exact words she used to describe them, but ugly factored, a lot.
Heat pumps will not work for me.

The link you posted appears to be a similar thing to a sunamp,  though I can only guess as it's somewhat light on detail.
If it is the same as a sunamp essentially using phase change material, the heat tops out at 57c iirc, which will probably not be enough for the radiators, certainly not if that's the highest it can reach (heat decreases as it depletes iirc)
Though when I last looked at sunamp they were talking about different phase changing materials to do different temperatures. 

If they did a phase change at say 65c then yeah, that could actually be installed under the floor and connect to the radiator loop to be used only in the dead of winter.... though usually cost is prohibitive for this kind of solution.
I'm not writing it off, just saying I've done a fair bit of research on various methods a year or so ago, and ive also spent the best part of 10k over the last few years between solar and batteries, so I cant justify another 6k on a heating solution, it's got to be *fairly* cheap.

What's most likely is I will go larger thermal store with heat exchanger to do both hot water (internal coil) and heating (heat exchanger) using the cheaper rate electricity for 80% of the time, and then take the hit for topping up heating in the dead of winter, hopefully offsetting the cost by the loss of the gas standing charge.

The other part is that I'm hoping my 15 year old combi is not so efficient, and so 75% efficiency means I really only need to cover 40 or so kwh in replacing it.

Maybe I can get away with 50c in the radiators, but I won't know that until I try, which brings me back to what I said earlier, I'm confident I can make it work for me, as I have a few different solutions. 
But that's me working around the problem.

Joe soap will not want to do this, and so the transition to pure electric will need more solutions than we currently have.

Coastalwatch, yes we have followed similar paths in some ways, i recall you got your thermal store (I plan on buying that same one on the back of your comments on it) at the time I opted for batteries, and you now have batteries when I'm looking to the thermal store.
We have similar sized houses, though mine is on 2 floors and about to become 3.
I'd guess the main difference is the extra bodies in my house, and perhaps the almost definite need to charge 1 of the two EV's every night meaning there will be less of the 25kw available purely for heating water.

NigeWick

Verdigris said:

I would have thought storage would be a no brainer for solar operators. Cream off the midday peak to sell at a premium price at teatime.

It's why I invested some of my inheritance in a Tesla Powerwall 2. I can use electricity from the battery at peak price times. I know it will take a long time to pay for itself but I could afford to be an early adopter. I also invested in the "gateway" that allows us to go off grid if there's a power cut.

gefnew

Hydrogen homes in Scotland trail.
The neighbourhood leading a green energy revolution - BBC News
This is to be run by national grid.

Coastalwatch

Solarchaser said:

Coastalwatch, yes we have followed similar paths in some ways, i recall you got your thermal store (I plan on buying that same one on the back of your comments on it) at the time I opted for batteries, and you now have batteries when I'm looking to the thermal store.
We have similar sized houses, though mine is on 2 floors and about to become 3.
I'd guess the main difference is the extra bodies in my house, and perhaps the almost definite need to charge 1 of the two EV's every night meaning there will be less of the 25kw available purely for heating water.

In winter we extensively use the overnight Go faster window to charge the EV(7kW), thermal store(3kW), 3 heated towel rails(750W), Oil filled rad(500W) and the two ashp's(1kW) so 12.25 kW's. Admittedly there will be another 3 or possibly 6 kW to add next winter for charging the batts but it seems to suggest that with 25kW available there shouldn't be an issue!

Martyn1981

QrizB said:

Martyn1981 said:

2nd_time_buyer said:

Verdigris said:

Is the wholesale price ever likely to get down to 2p/kWh?

I can foresee a danger in Johnson's statement, today, that he's going to take a huge gamble on nuclear. As you can't readily switch nuclear on and off, will wind and solar be forced to constrain to maintain grid balance? On the other hand, nuclear will never be cheap (unless fusion happens) so I suppose that will tend to support renewable prices, as long as we have somewhere to utilise it.

Which brings us back to storage...

I suspect (hope) the nuclear stuff was put in largely to appease the anti-RE demographic AKA the "what happens if the wind does not blow?" brigade.

The small nuclear reactors he is taking about are a very minimum of 10 years away from generation. Renewables are already forecast to roughly double by the end of the decade. It is conceivable, with a kick up the backside, they could triple and that would be pretty much enough. Nuclear will be too late to the party! 

The SMR's are the latest great hyped hope for nuclear, but I recall thinking the Rolls Royce proposal was virtually a joke, 4yrs or so back when I read the sales brochure they published. What stuck with me was (1) that they were 'hoping' for an eventual cost of £60/MWh, which back then RE was closing in on, and has now passed. Even if you ignore storage for nuclear, then that £60/MWh may have already been reached for RE and storage, which I tend to describe as (RE + (RE + storage)) to reflect the cost 'package'.

I agree that it's just boosterism, promoting RR because they're a recognised British brand and making people think that we're in some way leading the world.

If they were serious about actually building SMRs they'd use one of the existing designs, eg. the Chinese pebble bed reactor. (Pebble bed has been around for decades, Germany had one then South Africa got part-way through developiing their own before running out of money and building coal plants instead.)

"Boosterism", great summary, that makes a lot of sense. The RR reactors aren't even 'small', and if they can't be built in a single factory and shipped to location, then they won't benefit from economies of scale.

Having mentioned NuScale yesterday, I went on a Youtube hunt for something to listen to in the background, and hit the jackpot with a recent vid from 'Engineering with Rosie', which is just at my level (low!)

She looks at the SMR issues and chats with NuScale. I felt their situation was far more promising, even if it was likely to be a bit positive since they need to 'sell' the idea. But overall I felt the vid was fair and balanced.

Their approach involves smaller reactors, built at a central location. They are chasing $60/MWh, and hoping for a further 20% reduction after 6+ reactors. That compares reasonably(?) with wind and PV in the US at around $30-$40/MWh, especially when they suggested that their use might be to produce leccy for on-site hydrogen production for hydrogen based industries, such as fertiliser, which would help to decarbonise those areas. They also said that using waste heat allows for high temp electrolysis which is around 30% more efficient.

The suggestion here is that you have constant power, and a smaller footprint than wind or PV, though Rosie points out that PV can be building integrated or agrovoltaics, and wind has a small footprint, though it may require a large area.

Couple of small niggles/thoughts, NuScale claimed that their SMR's can demand follow, by reducing output with control rods, or diverting upto 100% of the steam away from the turbines. I suppose that sort of demand follows, but it seems more akin to curtailment to me, since the investment/costs of the reactor are still there, but you reduce generation with no cost saving, akin to PV and wind curtailment.

And Rosie summed things up well pondering why you would not want SMR's in the mix if they are safe and cheap. Which I do agree with, and is the same as my position which is why would you want nuclear in the mix if it isn't safe and cheap. Also that SMR's have been talked about for ages now, but not yet having delivered economically.

Crucially she raises the point that to address the climate crisis we need lots of good technologies, but not necessarily all possible technologies, and stresses that SMR's won't deliver till the end of this decade or the next at the earliest, so regardless they are not an alternative solution, and RE will still need to be rolled out as fast as possible. That's one of my big fears, sometimes described as 'delayism', where action/RE is delayed due to the promise of a future solution, such as clean coal / CCS for FF's, HFCV's to replace ICEV's,

Can Small Modular Reactors Save Nuclear Power?

Martyn1981

Weird thought, but perhaps worth posting this news item, which is nothing special, but just wanted to show that RE and storage is happening around the World, but perhaps doesn't get mentioned enough (certainly by me) due to the misapprehension that it's common and boring. That can then give the impression that nothing is happening, sorry.

Probably worth trying to post more such stories to show just how common it's becoming, and how we seem to now be moving into a storage phase as technology and costs improve (something that PV and onshore wind enjoyed last decade, and offshore wind in the last few years.)

Goldman Sachs toasts 390MW PV-plus-storage in California

Goldman Sachs Renewable Power has brought online its 390MW Slate solar plus energy storage project in Kings County in the US state of California.

Slate, which was originally developed by Canadian Solar subsidiary Recurrent Energy, has 561 megawatt-hours of storage capacity,

It is supported by power purchase agreements with five California-based organizations – Bay Area Rapid Transit, Central Coast Community Energy, the Power and Water Resources Pooling Authority, Silicon Valley Clean Energy and Stanford University.

Goldman Sachs Renewable Power head Jon Yoder said: “We are thrilled that Slate is now online and serving California-based organisations.

“There is significant demand throughout California for solar and energy storage projects at this scale, and we look forward to continuing to invest in projects like Slate that will help facilitate the state’s transition to a carbon-free power grid.