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The UK has enshrined in law the achievement of net zero carbon emissions by 2050. Energy independent homes form a key part of this puzzle.

As well as helping to reduce carbon emissions, energy independence can also help bring down energy bills for consumers.

Significant progress has already been made in making homes more energy independent. According to MCS figures, installations of both domestic solar PV panels and domestic battery storage systems are at record high levels.

On the one hand, both government and industry have helped facilitate energy independent homes. This includes the abolition of VAT on installations of domestic battery storage systems, among other measures. However, many hindrances remain when it comes to furthering energy independence.

Here, Dave Roberts, UK MD at energy storage specialist GivEnergy, explains the concept of energy independence and how to accelerate the development of energy independent homes.

What is an energy independent home?

Energy used to be a simple game. Households would draw from the electricity and gas grids, as and when required, then pay their bills accordingly.

The desire to reduce carbon emissions and energy bills, coupled with a rapidly changing energy market, is changing that model. Today, UK households are increasingly seeking energy independence.

For a small number of households, energy independence might mean living off-grid. (That is, disconnecting from the grid entirely.) However, for the vast majority of homes, being energy independent is a matter of degree rather than kind.

In other words, those looking to cut carbon emissions and energy bills usually take measures to make their home more energy independent — while still being able to draw from the grid whenever necessary.

For electricity, this can be achieved through:

• Renewable technology, including solar PV panels, wind turbines, etc.
• Battery storage, either coupled with renewable technology or as a standalone system
• Smart tariffs, for those who can take advantage of off-peak rates. (Usually through one or both of the above.)

Meanwhile, for heating, this can be achieved through:

• Heat pumps, most commonly air source heat pumps (ASHP)
• Solar thermal panels used to provide heating from solar energy

The rise of energy independent homes

Electricity

The increase in home solar installations is one of the clearest signs that energy independent homes are on the rise.

MCS figures show that of the almost 1.5 million solar panel installations in the UK, at least 519,409 are installed in homes. Domestic solar contributes to around 29% of total UK solar capacity.

While home solar panels represent a step in the right direction, renewable technology works most efficiently when coupled with a battery storage system.

According to a study published in Applied Energy, homeowners using solar panels without battery storage used only 30-40% of electricity generated. In contrast, those using solar coupled with battery storage saw imports from the grid decrease by 84%.

Fortunately, figures show that home battery storage installations are also on the rise. (Albeit at a slower rate than those of solar panels.) To use data from our own installer base, roughly 100 GivEnergy battery storage systems alone are installed per day across the UK. 57.2% of installers also say they are installing more battery storage systems compared to 2023.

Meanwhile, MCS data also indicates that a record number of home battery installations are happening.

Heating

The rise of heat pumps is also notable when it comes to energy independent homes.

The government aims to install 600,000 heat pumps annually by 2028. Compared with 2022, 2023 saw a 19% increase in installations of all types of heat pumps. Today, the total number of MCS approved heat pumps in the UK stands at more than 200,000.

While heat pumps offer a carbon-free alternative to gas boilers, it’s worth noting that they drive a subsequent increase in electricity usage. This increase needs to be managed in a way that won’t cause strain on the grid.

In fact, a report co-authored by the Centre for Net Zero suggests that — along with the electrification of transport — electric heating will cause annual consumer electricity demand to increase by around 50% per year by 2035.

One way to avoid this potential strain on the grid is to combine a heat pump with battery storage and solar PV panels. A stored supply of clean energy can help sustainably support even the most power-hungry heat pumps.

In fact, this combination has been explored by researchers at Fraunhofer Institute in Germany. The research found that pairing the above technologies can improve heat pump efficiency, while reducing reliance on the grid.

Facilitating energy independent homes

There is currently solid cause to be optimistic about the UK’s drive on energy independent homes. Let’s look at some examples from government and industry.

0% VAT

As of February 2024, all battery storage installations in the UK are VAT-free.

Previously, this only applied to battery storage systems installed alongside a solar PV array. This tax relief has now been extended to standalone battery storage systems, as well as retrofit storage batteries. (I.e., those fitted to an existing solar PV array.)

Zero Bills Homes

Introduced by Octopus Energy in 2020, properties included in the Zero Bills Homes initiative are guaranteed to have no energy bills for at least five years.

To begin with, the initiative is focused on new builds. Each property includes a smart meter, a home battery, solar PV panels, and a heat pump.

Zero Bills Homes is the result of cross-industry collaboration, including between:

• Energy supplier (Octopus Energy)
• Technology manufacturers (including GivEnergy’s provision of home batteries)
• Housing developers (Bellway Homes being the first national housebuilder to join the initiative)

Potential road blocks

On the flipside of the coin, it is also worth identifying some of the hindrances to the further development of energy independent homes.

The Future Homes Standard (FHS)

From 2025 onwards, compliance with the FHS will be mandatory for all new builds in England. The new standards aim to reduce carbon emissions by 75% per home.

Positives of the FHS include improved standards on insulation, the use of low-carbon heating like air source heat pumps, and ensuring new builds are smart meter-ready.

The latest consultation ended on March 27, 2024. While the inclusion of mandatory solar panels has been considered, the FHS still disappointingly fails to mention battery storage. This is despite a poll by MCS and YouGov showing that 61% of MPs support such a measure.

Home battery fire safety guidelines

In March 2024, the British Standards Institute (BSI) published PAS 63100:2024, outlining new guidelines for home battery installations. Section 6.5.5 states that batteries shall not be installed in ‘voids, roof spaces or lofts’.

The logic goes that roof spaces and lofts tend to have poor ventilation, exacerbating the risk of a battery fire. Moreover, lofts often contain flammable material, including insulation.

However, it’s worth noting the shift towards safer battery chemistry in battery storage systems. Many recorded incidents of home battery fires have been linked to nickel manganese cobalt (NMC) batteries, a type of lithium-ion battery. This battery type can be prone to thermal runaway.

Battery storage systems are gradually moving towards lithium iron phosphate (LiFePO4) chemistry, a type of lithium-ion battery with more stable cathode material less prone to thermal runaway.

Research by Fastmarkets suggests that in electric vehicles, energy storage systems, and consumer electronics, the proportion of LiFePO4 batteries will rise to 48% by 2033. (Compared with 26% in 2022.) Meanwhile, NMC batteries are expected to drop from 51% to 43% over the same period.

Given the gradual adoption of safer battery chemistry, it is conceivable that the guidelines around installations in roof spaces, and lofts may be subject to change.

For households with limited space, a loft installation may be the only feasible option when it comes to home batteries. In this respect, a change in the guidelines could make greater energy independence more accessible to more households.

Ensuring the further development of energy independent homes

Making more homes more energy independent is a crucial step towards achieving the UK’s net zero carbon emissions targets. Doing so means less reliance on the grid for our electricity and heating needs. Given the growth of solar PV panels, home battery storage systems, and heat pumps – significant progress has already been made on this front.

We’re also seeing how cross-industry collaboration can facilitate the development of energy independent homes. The recent abolition of VAT on battery storage systems and the introduction of Zero Bills Homes are two such prime examples.

Now, furthering energy independence should start with new build homes. An obvious starting point is the inclusion of battery storage in the FHS. This further development can ultimately help progress towards net zero, while helping to reduce energy bills along the way.