Low carbon Heating

   Efficient houses do not need expensive boilers & heating systems. Passive houses require very little heat input usually just the sun, people and appliances are enough, or a simple direct electrical heating device will suffice, such as underfloor or a simple plug-in heater.

   Heating with electricity at night can be much cheaper and generally has a lower carbon intensity than day time.   Switch your tariff to 100% renewable electricity such as octopus.energy to really lower your carbon footprint.

When To Heat ?

  Ideally electric heating should be storing heat at night when electricity is cheapest and greenest. Houses with a large thermal mass and good insulation can "coast" through the day. Maintaining temperature through the day.  

Export Tariff vs Night Tariff

  If you have solar PVs & heat pump combo you might want to use that to heat the house during the day, but UK solar export Tariffs have increased to 15p/kWh but night rate can be as low as 7.5p. making it more cost effective to heat, charge, wash etc at night and export during the day.

Heating types compared

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Air / Ground source heat pump ✅

Heat pumps give you more heat (or cooling) energy than you put into them, generally giving you 3-6 times the energy you have put into them.
Cheap and easy or big and expensive ?
This will depend on your House style, size & Insulation level.​

Air to Water Heat Pumps (with radiators)

   The typical air source heat pump, you are looking at costs ranging from £9,000 to £20,000.
​ You may have to change your current radiators for larger ones as the water in not as hot so requires a bigger surface area. You can "coast" through the day and heat at night on low tariff for further savings and when combined with solar PVs gives the greatest savings on energy costs.

Pros

• Can be powered by 100% renewable energy
• 3 - 4 times the energy in vs energy out
• ​Hot water ?
• Unit may last longer than 10 years
• Government RHI grant
• Can heat house at night on low rate

Cons 

• Very expensive Installation
  
• Big plumbing job
• High embedded carbon
• No Hot Water ?
• Radiators
• May require larger radiators
• Big whirring pump outside
• Ground source is even more expensive install
• Good insulation required
• May need a heat concentrator

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Heating & Cooling NO Radiators

   Air to Air heat pump kits can be bought for ≈ £750 and can be installed in a day. It generates roughly 2.5kW of heating or cooling for 670w of input. COP 3.7

Pros

• Requires no radiators
• Cheap
• Easy to install​

Cons 

• Won't give you hot water
• Only heats 1 room DIRECTLY
• Noise ?

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Further resources

Checkout the most efficient heat pumps at Heatpumpmonitor.org

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Heat Batteries

Some heat batteries store heat in hot rocks (500c) such as Caldera , others store as latent heat like those hand warmers you have to break to start off. They both have the advantage of being able to use cheap off peek electricity.

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Sun Amp

   Sun Amp Heat Batteries can be charged using any energy source. You can off-set peak energy costs by charging your Heat Battery with cheaper off-peak electricity, or divert energy from your solar PV, heat pumps or other renewable sources. Once charged, the heat can be released instantly when needed, delivering hot water and space heating during peak times.

Pros

• Can be powered by 100% renewable energy
• Utilises Cheap night rate electric
• ​Hot water included
• No gas standing charge
• Unit may last longer than 10 years​

Cons 

• Expensive Installation
  
• Big plumbing job
• High embedded carbon
• Radiators
• Whirring pump
• Good insulation required​

Caldera

Zero Emission Boiler (ZEB)

   The ZEB is powered by low carbon electricity - charging up whenever the grid is cleanest.

​    Working with time-of-use tariffs, the ZEB uses off-peak power to keep running costs low, roughly 1/4 of the day time tariff.

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Electric heater

   Running 1 or 2 oil filled heaters that cost a few pounds each could save you a fortune in installation. Run them on a timer if you ave cheap night rate

Pro's

• ​Can be powered by 100% renewable energy
• Quiet
• ​Very cheap n easy installation
• Ideal if renting a house
• Long Life span
• Low embedded carbon
• No pipes
• No gas standing charge

​
Con's

• No Hot Water
• High energy costs / kWh £0.12 - £0.45
• ​​Only heats one room although heat will permeate through the whole building.​
• Ugly
• Good insulation required​

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Bitcoin mine heating

   Imagine an expensive hair dryer that just happens to make money ! Bitcoin mining hardware (ASIC's) blow out lots of warm air 40c (104F), why not use it to heat your house?
​   Power it with 100% renewable electricity and you have zero emissions heating. Once set up it's just a matter of flicking a switch or setting a timer to turn it on. Then eventually selling (or not) the resulting Bitcoin to pay for the electricity.

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Pros

• Can be powered by 100% renewable energy
• Makes Bitcoin. Bitcoin pays for the electricity
• No radiators
• Low Install costs
• No gas standing charge
• Can heat most of house if well insulated
• Good air quality / Filters dust from the air
• Low quantity of materials required
• Ends business monopoly on "wasteful" mining​

Cons

• Replacing ASICs every 2 - 4 years
• Whirring box
• Selling Bitcoin if not tech savvy
  
• Too complicated for most people​​

   Here's a breakdown / comparison between ASIC heating vs Gas boiler. More mining info here
​www.thehodler.info/mining

Wood Stove

   Everyone loves a wood stove (apart from the neighbours) . I have a wood stove as a back up if there is a power cut.

Pros

• Looks and feels comforting
• Theoretically low (net) CO₂
• Good backup if the electricity goes off
• Low cost fuel ?
• Can cook on a flat top stove at a pinch
• ​Off grid
• Can heat water

Cons

• Smoke from the wood can be toxic
• Can upset neighbours
• Poor air quality indoors
• Sourcing wood
• Chopping wood/sticks
• Continuous tending the fire
• Can vent warm air when not in use wasting valuable heat via Siphonage
• Can draw in smoke when in use via Siphonage (see picture)