As our Property Investor Report (pdf 4.6 MB) Opens in a new window revealed, a lot of work is needed to bring the UK’s housing stock up to increasingly demanding energy efficiency standards. With an ever-increasing focus on what we can do to make our buildings greener and more energy efficient, here we take a look at some new green technologies that could one day be the norm in the race to reach our net-zero targets.
Transparent solar energy
The sun has long been our friend when it comes to renewable energy, and solar panels are becoming an increasingly efficient way of generating low to zero-cost electricity or warm water. Could the next step be transparent solar panels? This technology harnesses light through windows and glass surfaces turning it into energy. Whilst tentatively in use in larger upgrades (see the technology in action cladding the Copenhagen International School Opens in a new window), there’s still some way to go however, as scientists work to make scaling-up the solution more efficient and viable for our homes.
Hempcrete
A relatively new alternative to insulation and concrete hempcrete or hemplime is made with the woody pulp of hemp, mixed with lime and water. It’s durable, airtight, resistant to mould and pests, toxin-free and does a better job at storing heat than concrete and masonry. It can be used to form walls and to insulate the roof of new-builds, and for upgrading insulation in existing buildings; due to the way it sets hempcrete is ideal for insulating more traditional or historic buildings with tricky layouts. The use of lime in its production does have a carbon cost due to the heat used as part of the process, however as hemp absorbs carbon as it grows it more than cancels that out, making it carbon negative. The production of hemp is very quick, taking only four to five months to grow and harvest.
However, hempcrete is unlikely to replace building materials such as concrete because it is unable to endure heavy loads. Also, it’s unsuitable for foundations as it cannot withstand moisture / water for long durations. Nevertheless, hempcrete offers a variety of applications and could still become a mainstream building product.
Micro hydro generation
Working on the principle that moving water can generate energy, micro hydro generation installations divert water flow from a river, stream or waterfall, to a turbine to produce electricity, before returning the water to the source. Whilst micro hydro may not be seen on suburban estates any time soon, it could come into its own if a large property such as a farm has a water source running through it. For more rural areas where fast flowing water is a feature, community micro hydro installations could be an option to provide renewable energy to the surrounding homes.
Mechanical ventilation and heat recovery
These units – and the network of ducts that feeds into them - work by extracting polluted or stale air from the property, pass it over a heat exchanger to retain the heat from that air, then feed-back that recovered heat into the home’s air flow. It’s sustainable energy technology that can work with other renewable heating systems. Its perfect partner is a heat pump which also uses heat exchangers to multiply natural warmth in the air, ground or water outside into space heating and hot water - when the two technologies work together they’re even more energy efficient. Trickier to retrofit into homes than installing into new-builds, they could mean an end to radiators or underfloor heating, they would however also mean the end of cosy winter nights in front of the fire, since the system can’t work with open fires or wood burners.