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Decarbonising your home to save money

Decarbonising your home to save money
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Warmur is the missing home energy calculator, helping homeowners to visualise their energy bill savings from the wholesale electrification of their homes. We're launching October 2023.

Last 12 Months vs Next 12 years

Most cost-saving calculators focus on showing estimates of future energy bill savings, extrapolating future energy prices rising at 4-6% per annum. In our view, this approach is fundamentally flawed and ignores the variability that can result from changes in geopolitics, supply mix, government policy and more. We believe that the Black Swan event in energy pricing is that there are no energy price shocks over the coming years.

DESNEZ Data, See 1) & 2) below

Instead of pretending we have a crystal ball, Warmur uses a retrospective approach. By asking you for your annual energy usage (printed on your gas & electricity bill), and knowing a few facts about your home, we can paint a picture of how your last 12 months' energy bills might have looked had you moved to a range of low carbon technologies.

Time of Use Tariffs

There has been significant growth in interest in time-of-use tariffs, rewarding consumers with cheaper electricity prices in return for shifting demand. Most major energy suppliers now offer a 'time-of-use' tariff for electricity consumption: at the time of writing Octopus offered at least 5 variants. As the UK electricity supply mix is increasingly dominated by intermittent renewables, we believe that time-of-use tariffs are here to stay and can help many home owners save on thier bills. The real consumer benefits of time-of-use tariffs emerge when homeowners increase their electricity usage by switching to Electric Vehicles (transition well underway) and Heat Pumps (transition imminent: post coming soon!).

UK Electricity Production, source: grid.iamkate.com

But homeowners are justifiably bewildered by the choices of different time-of-use tariffs available. It's no longer feasible for a homeowner to fire up excel and work out the best tariff for their usage pattern, even if they have access to smart meter data. Warmur tracks time-of-use tariff pricing and can recommend a tariff which would have been optimal, based on the electrification measures applied to the home.


Warmur asks questions about your home and habits, and combines these with historical energy prices, climate and buildings information sources. We use this data to predict heat pump running costs, electric vehicle home charging costs, solar generation and battery sizing. We do this by computing electricity usage, generation and storage data for every 30 minute period for the last calendar year.

Based on this model, we can calculate estimated bills, on the assumption that you had executed a wholesale decarbonisation of your home. Better still, we'll let you turn certain improvements on or off, so you can see which interventions might make the most financial sense for you.

Subscribe to stay informed about when CarbonFreeHome.co.uk is launched, or email us if you have comments or questions. We're busy developing our software model and would love to hear from you!

  1. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1126041/table_231.xlsx
  2. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1126037/table_221.xlsx