We’ve been investigating local energy usage, and the opportunity to remove carbon emissions completely, as soon as possible.

We believe it’s possible to completely remove carbon emissions from your home and workplace.  We think it can be done very quickly; potentially within 12 months.  It’s a bold statement, so please bear with us…

NB: This page makes several references to the Agile tariff by Octopus Energy.  We have no commercial relationship with Octopus (except that the Author is a customer).  We just think they have some interesting, innovative products.  If you know of anything comparable, PLEASE let us know.

  1. Step One – Switch to Green Electricity and Gas Suppliers to avoid Carbon Emissions
  2. Step Two – Install a Smart Meter to understand your energy usage patterns
  3. Step Three – Install Battery Storage to use cheap electricity
  4. Step Four – Install a Heat Pump to replace your Gas Boiler – No more Carbon Emissions
  5. Step Five – Install Solar Panels to make Free, Green Electricity

You may like to read our guide to CO2 emissions, and why they’re bad.

Step One – Use Green Energy Suppliers

Clean Energy

There are two types of energy supplier:

  • Clean, that deliver energy that is carbon-free, clean, efficient, and surprisingly…cheaper to make.
  • Dirty, such as that coming from fossil based energy such as coal, gas, oil, etc.

It’s imprtant to know which is which.

Simply by switching your energy supplier, you could save the emission of 5 Tonnes of CO2 per year.

There are lots Green Energy suppliers, but beware of  suppliers that make thier product sound green, but in fact it’s not as green as other products (Green Washing).

For many people, who rent their property (for example) this will be as far as they can go…..but it’s pretty far.

If you’ve done this, and adopted a Green Electricity tariff, and Carbon Offset Gas Tariff, you’re doing pretty well….better than most people, and you can be proud.

The following steps are for people and businesses with a little more autonomy about their energy and heating systems.

Step Two – Smart Meters


  • Summary
  • Detail


It cost you nothing to get a Smart meter installed by your energy supplier.

The Smart Meter will help you understand your hourly use of Electricity and Gas.

There wil be be no more Estimated Bills, so no more shocks when you have large back-payments.

The UK Government is trying to get all property owners to install Smart Meters by mid 2025, with the benefits of avoiding estimated meter readings, and therefore, no surprises in bills.  The Smart Meter includes an In-House-Display, allowing property owners to monitor their energy usage throughout the day (electricity and gas).  The expectation is that when property owners understand their usage, they can manage it better, and that energy consumption (and bills) will be reduced.  Installation of the Smart Meter is free to the customer, and is paid by the energy supplier.

A Smart Meter will monitor:

  • Gas imported from the National Grid
  • Electricity imported from the National Grid
  • Electricity generated by Solar Panels
  • Electricity exported from Solar Panels to the National Grid

This will provide you with very detailed information (every 30 minutes) about your energy use through the day; when you use most energy, and when you use least.  In the UK, Smart Meters are free, and the Government intends that we will all have them.

 Ask your energy supplier to install a Smart Meter as soon as possible, to replace your current meter, and get the benefits soon.   

You will get an In House Display , and a web portal to your account that you can login to, and download your usage information.

You can then use the information provided by the Smart Meter to help you plan the following steps.  Don’t hang around waiting – suppliers are behind the curve with installations, and you may have to wait a while to get your installation !!

Step Three – Store & Save

This is will save you money, and helps you to maximise your benefits from Step-4 and Step-5.

  • Summary
  • Detail
  • More about Battery Storage

By deciding WHEN to use electricity, you can save money, and help the planet at the same time.

Some electricity suppliers provide tariffs with prices that follow National Grid’s supply and demand prices.  Prices are usually lower than the fixed prices available on most tariffs.

You can buy batteries to store electricity, so you can buy cheap electricity, then use it when when the electricity prices are high.

Some times of the day have a higher demand for electricity than others (the classic example is the commercial break in Corronation Street, when everybody makes a cup of tea).

The scrabble for demand means that suppliers fall back to less green sources of energy.  Because demand is high, they charge a higher price for it.  Most people don’t realise this is going on, because they have a fixed price, and their supplier manages the variation in spot-price through the day and year.

It’s worth noting that every tariff takes energy from a variety of sources and power stations (Wind,Solar, Nuclear, Gas, Coal, etc.).  Even dirty-tariffs include some green electricity,as green electricity is cheaper than other sources.

When electricity is in short supply, Green-Energy is bought (for green-tariffs) and sold (to us), leaving a shortfall for dirty-suppliers who then fall back on dirty-sources to fill the gap.  Typically these are gas-fired power stations that can be quickly enabled to fill the demand gap.

As a consequence of all this movement in generating capacity and mix of sources, we can look at the spot-price as an indicator of green-ness in the National Grid.

Each day, the National Grid divides the 24 hours into 30 minute segments, and generators bid a price to sell their generating capacity for each 30 minute segment, depending on what they think the market will stand.  Retailers (such as Octopus, Bulb, Ovo) place contracts to buy energy from a variety of the sources, for each 30 minute segment.  They then decide what price they will charge their customers.  For most people, the price is averaged over the year into a fixed price. 

There are innovative new electricity tariffs (such as Octopus Agile) with dynamic prices that change through the day, depending on how scarce electricity is at that time.  The chart shows the half-hour spot price for electircity (on the Agile tariff).

The intention is that customers can choose when to use their electrical devices, and that suppliers can influence demand, and optimise their power delivery contracts.

The Ocotpus Agile tariff publishes the spot-price for the coming 36 hours, in 30 minute segments.  Prices can vary from 32p/kWh at peak times, to 3p/kWh at times of low demand.  In extraordinary times, the price can even be negative (they pay us to use electricity)!

In practice, the spot-price reflects demand, and the activity of dirty-generators.  The higher the price, the dirtier the national supply).

Energy Storage Systems (ESS) provide a way to buy electricity at low price, store it, then use it later in the day when demand & prices are much higher.

Energy Storage systems are really intelligent Batteries, that can be programmed to charge, say, overnight, and discharge (power our bulding) during the evening.

This technology came out of the Solar Panel industry (more of this in Stage 4), when people recognised that Solar Panels operated during the day, but not at night…People wanted to use the electricity that they had generated.  We can use the same technique to Charge overnight, and Discharge in the evening.

Ther are several suppliers of battery storage (ESS) technology, and prices have fallen dramatically over the past 5 years.

Currently, using ESS and Agile (green) energy, the Return On Investment period (ROI) is around 5 years, and the units have a design life of 15+ years.  If we adopt the following steps, the ROI comes down to around 3 years!


We’ve not verified these suppliers; they’re included to show their breadth:

  • BYD
  • Givenergy
  • Pylon Technologies
  • SMA
  • Varta
  • ….and many more

Typically, there are three major components that you need:

  1. Your current Consumer Unit / Fuse Box / Distribution Panel
  2. An Charger/Inverter that will charge the battery pack when electricity is cheap, and power your property from the battery when electricity is expensive.  If you already have (or are thinking of getting) Solar Panels, you may like to consider a Solar Charger that will also charge you battery from your Solar Panels during the day, for free.  Solar Chargers also consider Weather Forecasts and Sunshine Hours in deciding when to charge your battery.
  3. One or more batteries, to hold enough charge to get you through the 3pm-8pm period of increased demand.  Typically, a single inverter supports between 1 to 16 batteries (depending on manufacturer).

We will probably add a page about designing your system, but that isn’t available at this time (as we develop our website).

You may already know when you use most electricity, but your Smart Meter will confirm this.

You will see that the price is highest in the evening (with high demand and dirty electricity).

If you can charge your battery before 3pm, and use battery electricity between 3pm and 8pm, your electricy price will effectively fall below 10p/unit….possibly falling to around 7p/unit depending on how clever your battery management system is.  

If we can shift our electricity usage outside the evening high, we can reduce the reliance on dirty electricity, and do ourselves a favour, by not paying the peak price.

Step Four- Heating & Cooking

In the few buildings we have looked at, on an annual basis we use 3 x more energy heating our property, than is used to power electrical devices.  Most of this heating uses a dirty gas supply.

Here’s a handy calculator to figure out how much CO2 we create when heating our homes: 

Annual usage:

 (you should be able to find your annual usage from yout energy supplier)

Obviously, it would be great to find a way to reduce our carbon footprint to zero.  The answer is the “Air Source Heat Pump’.  The big surprise is that the government will pay for it !!!

Government Grants and Incentives

The UK Govenment frequently offers a financial payment to householders and businesses that replace their Fossil Heating system with a Renewable Energy System. The schemes change like the wind, so please check for current funding.


Air Source Heat Pump (ASHP)

An Air Source Heat Pump would replace (or, sometimes work with) our gas boiler. and hot water cylinder..

  • Summary
  • How They Work
  • They’re Not All Equal
  • Saving Money with a Heat Pump

Heat Pumps bring heat into your property, from outside.  They work exactly the same way as your refrigerator….but in reverse.  This isn’t new technology, but it’s not yet common in the UK.

They work in eactly the same way as a refrigerator.  Have you ever felt how warm is the pipework behind your fridge?  Heat in the air inside the fridge is being extracted, and given out from the pipework behind..  Imagine the fridge turned inside out, with the “cooling elements” outside, and the warm pipework in an insulated box; it would get pretty warm in there.  This is eactly how the ASHP works.

When you compress a gas it gets warm (like compressing a bicycle tire pump).  This heat is transferred with a heat-exchanger to the water in your radiators and hot water tank.  Any remaining heat in the gas (after passing through the heat-exchanger) is then allowed to cool, outside your building.  Now the gas is re-compressed, causing it to warm up….and so on.

Remarkably, it takes less electrical energy to comress the gas, than the heat energy brought into the house.  This ratio is the Coefficient of Performance (COP),  Typically, the COP of an ASHP in the UK will be somewhere from 3 to 6, depending on the design criteria of the specific Heat Pump..

In the UK, it’s safe to assume a rough COP = 4;  i.e. 1kWh of electricity delivers 4kWh of heat.

This is much better than a ordinary electic heater, which would have a COP nearer to 0.8 (1kWh electricity gives 800Wh of heat), or an electric radiator (COP=1)

Admission No. 1:  We’re still learning about Heat Pumps, so please verify the following, and let us know if things need correcting.

There are two primary types of Heat Pump:

Split PumpsMonoblock Pumps
OUTSIDE THE BUILDINGCooling elements (Expansion Unit)Relatively smaller componentINSIDE THE BUILDINGBoiler size componentHeating elements (Compressor)Hot Water TankJOINING PIPEWORKContains RefrigerantREFRIGERANTSeveral kilograms (i.e. lots)OUTSIDE THE BUILDINGCooling elements (Expansion Unit)Heating elements (Compressor)Relatively larger componentINSIDE THE BUILDINGHot Water TankJOINING PIPEWORKContains WaterREFRIGERANTSmall amount (components are close together)

From the perspective of Global Warming, Refrigerant is a significant consideration.  If refrigerant should leak from the system, it will leak into the atmosphere, where we should consider 2 factors:

  1. Ozone Depletion Factor: This used to be significant, but since the global ban on CFCs (ChloroFluroCarbons) most refigerants are Ozone Friendly
  2. Global Warming Potential.:  By international standards, CO2 has a GWP of “1”.  Some Common Rerigerants have significantly higher values for GWP of 660 (R32 – 1kg of R32 is equivalent to 650kg of CO2),  up to  4300 (R420a – 1kg of R420a is equivalent to 4 TONNES of CO2).

As environmentalists, we shiould be extremely sensitive to the Refigerant in use, and the volume of that refigerant.

It’s worth noting that some Heat Pump manufacturers now use CO2 as a Refrigerant, and there are some Refrigerants with GWP less than “1”.  We expect these to become more common as the takeup of heat Pumps increases.

The Air Source Heat Pump is a critical part of our plan.

It’s well known that 1kWh of electricity is more expensive than 1kWh of heat from gas (by a factor of about 4 (16p vs. 4p per kWh).  The trick here is to reduce the price paid for electricity to achieve 1kWh of heating.

Previously, we descried how an ASHP with COP 4 could deliver 4kWh of heat from 1kWh of electricity.

So, using an ASHP with green electricity costs the same as burning dirty gas in a domestic boiler.

Now, if we also wrap in the price reductions from the Energy Storage System of Step-2, we see that the ASHP costs roughly half the amount of money to deliver the same heat.

Win on Carbon reduction.

Win on Cost savings

Step Five – Negative Carbon

Previous steps have reduced the carbon footprint of our building to zero, and liberated energy that we were consuming, so that other people can use it.

Solar Panels generate a substantial amount of electricity each year, with no trouble, and they will do it for 25+ years.

Our final step is to generate electricity for ourselves, and for others. 

Using Solar Panels, we can either:

  • Use the electricity ourselves, in real-time, for our building and services.
  • Charge our own Energy Storage System installed at Step-2, and use it later in the day, ourselves.
  • Export any surplus electricity to the National Grid, to support green-energy, and get paid for each kWh we export.

Using our self generated electricity, reduces the amount of electricity that we import ot our building, and therefore reduces our energy bills (remember that we’ve also stopped using gas, so we have no gas bill to pay).

The reduced energy bills  compensate for the installation cost for the Solar Panels, ESS, and ASHP, thus reducing the time to our Return on Investment.


We’ve seen how we can use existing technologies, products, and financial incentives to deliver a negative Carbon footprint with some well timed, and cooperating installations into our buildings:

  • Green Energy Tariffs for Electricity
  • Carbon Offset Tariffs for Gas
  • Energy Storage System to make use of spare electricity, and avoid using dirty electricity at peak times
  • Air Source Heat Pump to replace Gas boilers, using less energy
  • Solar Panels to displaces dirty electricity on the National Grid, reduce our costs, and reduce our Carbon Footprint below zero

Every installation will have its own specific attributes, around physical space, available finance, timescales, and so on.  Your installation will be unique, but aligned with a common-good.

We intend to publish a checklist, programme of work, suggested suppliers, etc.

If you would like to contribute to this pool of knowledge, please register, and fill in the comment box, below.

Remember, the first step, is to take the first step.