Dual Fuel Boilers (Electric + NG) to solve heating and curtailment

With the UK grid more or less solved with what has been built, what is under construction and what is committed to. We must move onto heating.

There are lots of wild ideas about heating and how to use excess wind/pv rather than curtail it

The solution is actually quite easy. Government just regulates so all boilers are dual fuel and smart. To add a 11.5 KW electric heater to a boiler will cost maybe £20 (since you can buy an electric shower for £50 retail) and to make it wifi smart perhaps another £20 (you can buy a cheap smartphone for £50 and a boiler does not need most of what is in said phone, eg 4g/speaker/battery/microphone/camera/etc)

With dual fuel boilers replacing gas boilers as they come to the end of their lives you just have the grid or energy companies tell the boilers to use their electric elements when we have excess wind/pv and to use their NG side when there is no excess. Users are charged only 5p for the electricity the boiler uses and the customers are fine with this since it displaces NG at 4p but only 75% efficient so = more than 5p so a small saving for them.
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Replies

  • edited 20 June 2019 at 5:11PM
    GreatApeGreatApe
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    edited 20 June 2019 at 5:11PM
    Not only does this solve any near future curtailment grid issues but it allows future proofing of heating and the cost is small (only about £40 perhaps less, per boiler, to add electrical element and smart capability)

    It also allows hybrid heating solution and will allow the UK to decarb heating via offshore wind power

    Once the grid is solved circa 2025 we have to move onto heating

    Offshore wind (40% annual CF but 50% CF in the winter with a 75% correlation in max output over a wide area like the UK) could provide 66% of average winter heating needs and likely more than that of summer needs. When the wind blows hard these hybrid boilers are electrically heated. When the wind does not blow enough they are NG fueled

    This idea will allow much more wind power to be deployed much more quickly.
    Start regulating this for all boilers installed from 2025 onward which will be circa 2 million boilers replaced per year and by 2040 the majority of gas fired boilers will be duel fuel

    Without this idea we will soon hit the more and more curtailment wall circa 2025
    But with these hybrid boilers the more wind you build out, the more natural gas is displaced out of heating so we could just install a lot more wind from the period 2025-2050 than could be possible without this idea

    As an estimate this idea could allow as much as 80GW more offshore wind power capacity onto the UK grid than without these hybrid boilers (National and local grid capacity allowing)
  • Reed_RichardsReed_Richards Forumite
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    I think you probably need a thermal store to be used in conjunction with the boiler so you can run the boiler when it is cheap to do so and extract the heat when you actually need it. Either that or you have a big battery and store electricity when it is cheap.
    Reed
  • GreatApeGreatApe
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    I think you probably need a thermal store to be used in conjunction with the boiler so you can run the boiler when it is cheap to do so and extract the heat when you actually need it. Either that or you have a big battery and store electricity when it is cheap.

    You need a simple cheap plug and play system. IF someone has a combi as many homes and businesses do then you dont want to make it so they have to get rid of that and buy a huge tank find somewhere for it pay for additional plumbing etc

    Adds cost and complexity and many people dont really have the space for a large tank. A tank also loses energy for standing losses my tank close to 2KWh a day in lost heat just sitting there. And water tanks dont really offer a huge scope to store a lot of energy. A 200 litre tank allowed to cycle from 50-70 is only 4-5 KWh of storage

    Instead you can have the smart boiler allow thermal storage via the house itself. So if the temp is set to 20 centigrade allow it to cycle between 19-22 this three degree of heat might have storage in excess of what the tank does and would cost nothing
  • GreatApeGreatApe
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    With this system every time a boiler wants to fire up it send a message to the utility which says either ok use electric or dont use electric depending on how much excess renewables are on the grid. The response would only be something like 0.1 second delay so not even noticeable

    Especially in the colder months many people have the heating on constantly especially in colder areas like Scotland where in some homes it might be on for 6-9 months of the year. So a huge amount of winter output can be put through these hybrid boilers and offshore wind output in the winter is ~50% CF

    The heating can also be pulsed to allow it to be controlled all the way from zero to 10KW and anything in between or have 10 controllable elements to allow different levels of output. Where electricity line is limited or difficult to add a bigger line the boiler can be set to 3KW max so it can dual fired on high heat applications (eg shower) or use pure electric on lower heat application (radiators).

    This idea works well because it is extremely cheap to do
    You can buy an electric shower for £50 retail which means the cost to make it is probably closer to £10 and the additional bits for these hybrid boilers would be no more (in fact much less) than what is in an electric shower. Boilers should also be made smart and connected to wifi which almost all homes have (if you dont got wifi it can operate on pure gas mode). The brains of said boilers would be much less than the cheapest smartphones which cost £50 retail but again £10 to manufacture especially since most of this (smartphone) is unnecessary (speaker, microphone, bluetooth, 4g cellular, gps, etc, all unnecessary) and these smarts are also nice for the consumer as they can set the temp via their smartphones and turn the heating on off via their phones and even diagnose problems etc via the smartphones

    The cost is going to be somewhere in the £20 range to make these boilers smart and better for consumers

    With them in place you can add more and more and more offshore wind power and the more you add the more these stock of hybrid boilers use electricity and less of natural gas


    Really what is the downside if you do this?
    Consumers pay 1-2% more for a boiler
    Even if they never use the electric side they get a boiler they can control with their smartphones

    You could also use some software to temp them to use less energy with simple prompts. Do you know you could save 20% by reducing the temp by 1 degree. Accept?

    Also a lot of problems can be diagnosed via these smart boilers. Eg I knew one person who had their boiler hot water temp set to I dont know 60 centigrade, but their tank was set to 65 centigrade so the tank was constantly asking for heating but it never got up to temp becuase the boiler was only sending 60 centigrade water. This setup was like this for 5+ years before I fixed it. During that time the pump was running 24/7 at 90 watts and the pipework was emitting lots of lost heat between the boiler and the tank perhaps as much as 500 watts. At Least 25MWh of NG wasted and at least 4 MWh of electricity wasted due to incorrectly setting up the system. Easy fix was just to set the tank to want 60 centigrade and the boiler to output 62 centigrade. Such a customer with a smart boiler could have been notified there is a problem (eg easy software to realize the thing should be on 24/7 for months at a time) and to notify what the problem might be too or to call a plumber. Said person would have saved ~£1,600 if they cough the problem 5 years sooner or had the £20 smart hybrid boiler rather than a dumb boiler
  • markinmarkin Forumite
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    A new kind of smart meter with time of use tariff could just tell electric rads/ heat pumps to turn on/off min to min, to use wind and solar, that is the point of the tariff is it not? and a hot water tank could go on the wall in place of a boiler, or you could just install both systems side by side for now.


    Storage from night to day in water or storage heaters still makes sense to even out the usage, unless ev's end up using it all
     
  • Andy_WSMAndy_WSM Forumite
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    The local distribution grid won't cope with lots of 12kW heaters all switching on at the same time to soak up excess wind generation. The capacity (as things stand) just isn't there. If it was then electric car charging (which "only" uses 7kWh, some only 3.6kWh, for the majority of current cars) wouldn't be a topic of discussion.
  • GreatApeGreatApe
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    markin wrote: »
    A new kind of smart meter with time of use tariff could just tell electric rads/ heat pumps to turn on/off min to min, to use wind and solar, that is the point of the tariff is it not? and a hot water tank could go on the wall in place of a boiler, or you could just install both systems side by side for now.

    Storage from night to day in water or storage heaters still makes sense to even out the usage, unless ev's end up using it all


    My idea requires no changes whatsoever just a regulation which adds about 2% to the cost of a boiler but gives customers a smart boiler which is worth the 2%

    Installing electric storage heaters
    Or tanks where there were no tank
    Or heat pumps where there were no heat pumps
    Those ideas cost significant amounts and cause the owners problems

    This idea should be done even if there was no issues about climate or curtailment.
    It offers customers a smart combi boiler with a backup electric element for when/if the gas side stops working they have heat. The smart system can also diagnose various problems and help the consumer

    Just look at it as a side benefit that the electric dual fuel function could allow significantly more wind power into the grid without having to curtail or magic up mass hydrogen chemical plants

    These boilers could allow significantly more wind power into the UK and EU grids. The more wind that is installed the more the fleet of hybrid boilers run on surplus electricity rather than NG
  • GreatApeGreatApe
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    Andy_WSM wrote: »
    The local distribution grid won't cope with lots of 12kW heaters all switching on at the same time to soak up excess wind generation. The capacity (as things stand) just isn't there. If it was then electric car charging (which "only" uses 7kWh, some only 3.6kWh, for the majority of current cars) wouldn't be a topic of discussion.


    And where the local grid is at capacity when the boiler sends its signal to the utility to ask 'gov electric or gas?' it gets the answer gas back. Where there is capacity in the local grid, it gets a signal back saying 'use electric me lad'

    Location of where the boiler is can be determined by GPS (like even the cheapest smartphones have) or the postcode entered on registration when the system is installed

    Also 12KW is overkill, most of these boilers will only be connected to the existing 13A connection rather than a new thicker wire installed. But 12KW or 3KW both will be controllable so its not 0 or Max but variable between 0 and Max. A typical house would use closer to 2-3KW for its radiators in the winter anyway so doesn't need much more. For higher demand applicaitons like the shower you might have the gas side provide 8KW of heat and the electric side provide 3KW of electric to combine to 11KW to feed the shower

    Also any local grid capacity limits will be only during certain times of the day. Plus the grid connected to the housing stock has a lot more capacity than average usage. Heating wont be a problem at all with maybe a 24h heating cycle the utility telling the boiler to use gas for 2-3 hours the rest of the time there will be capacity

    As for the national grid and if it has capacity. The UK grid does have a lot of spare capacity since in the recent past the UK grid was handling about 20% more energy on winter days than we currently do (because energy efficiency has allowed peak demand to go down by about 10GW over the last decade or so)

    This is a very very good idea and has no downsides
    The only downside is boiler costs go up 2% but you get a better boiler
    Even if your boiler lasts 15 years and never ever uses its electric side becuase your local grid is congested or there is never ever excess wind power on the grid...what have you lost? Nothing!

    But it means if the nation decides to install a lot more wind, instead of curtailing it these hybrid boilers make use of the energy and save NG
  • edited 21 June 2019 at 8:22PM
    GreatApeGreatApe
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    edited 21 June 2019 at 8:22PM
    Andy_WSM wrote: »
    The local distribution grid won't cope with lots of 12kW heaters all switching on at the same time to soak up excess wind generation. The capacity (as things stand) just isn't there. If it was then electric car charging (which "only" uses 7kWh, some only 3.6kWh, for the majority of current cars) wouldn't be a topic of discussion.


    Whatever the capacity of the local grid is, that many boilers will be told to use electric if and when there is excess wind power

    So if in your neighborhood there is 1,000 homes all hybrid boilers, some 3KW electric some 12KW electric

    If it is winter and there is only 1MW spare at 7pm in that local line and say everyone has heating on. Well the utility can tell 333 of the homes 'ok lad you can use your 3KW electric heater' the other 667 hybrid boilers would be told 'not now'

    If at 9pm in that local grid there is 2MW spare capacity it can tell 667 of the homes 'ok lad use 3KW electric' and tell 333 homes 'not now'

    These boilers can ask every minute, even second by second its not like the data rate would be high. So the local grid will never be exceeded

    Even if an individual boiler is never used on electric mode there is no loss to the owner or the country. The only loss is £20 more expensive boiler over a 10-20 year boiler life and even that is no big loss as you get a smart boiler rather than a dumb boiler (eg you could change temp on your phone or diagnose problems on your phone etc)

    There is literally no downside
  • markinmarkin Forumite
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    I don't think more than 20% would be able to use the elec at once if 12kw, I don't think 3kw would instantaneously heat water to run a tap unless its a separate water heating supply and that may as well be under the sink.


    Now Co-firing 50% of the time at 3kw would save some gas but is it worth it?
     
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