One of the big questions for environmentally-minded homeowners is how to make their homes more sustainable and energy-efficient. There are some more obvious switches one can invest in, like installing small wind energy systems or household hydropower systems, however, there are also many lesser-known clean energy innovations that are worth considering. 

Solar paint

Imagine the power of solar panels being infused into paint! This technology isn’t yet commercially available, but there are various solar paints already in development. The idea is that solar paint would allow you to generate solar energy directly from any large painted surface with sunlight exposure. It could also potentially boost the efficiency of conventional solar panels.

Some of the different kinds of solar paint being developed include:

Colloidal quantum dot solar cells

A photovoltaic paint made of light-absorbing nanoparticles spread over a special film created by a team from the University of Toronto.

Perovskite solar paint

A light-absorbing and semiconducting material that turns solar energy into electrical energy. Researchers from the University of Sheffield figured out a way to spray liquid perovskite cells onto surfaces back in 2014.

Researchers at MIT built upon this idea and in 2019 concluded that incorporating a layer of transparent coating material on top of this kind of solar paint significantly improves its electrical conductivity.

Hydrogen-collecting solar paint

The Royal Melbourne Institute of Technology developed this solar paint, which uses a compound called synthetic molybdenum-sulfide. This compound absorbs water from the air and acts as a semi-conductor, using energy from sunlight to split water atoms into hydrogen (a source of renewable energy) and oxygen. Mixing the compound with titanium oxide particles could result in an ingredient for sun-absorbing, hydrogen-generating paint

While we wait for these paints to become refined and available on the market, we can still use paint to make our homes more energy-efficient. Solar reflective paint reduces heat build-up within the home, thus reducing the need for air-conditioning and lowering energy usage.

Solar thermal fuel and home-made water battery

The thing about solar power is that solar panels are most effective on sunny days. When the weather outside is grey and cloudy, solar panels usually work at only 10-25 percent of their efficiency.

Even though solar energy that is stored in batteries can keep a solar-powered home running even when the sun isn’t shining, the storage solution isn’t large-scale, prompting scientists to develop alternatives.

Well, Swedish scientists have come up with a clever way of storing solar power for up to 18 years by developing a liquid “solar thermal fuel” that functions like a rechargeable battery (for solar rather than electric power).

A DIY solution in the same spirit as the solar thermal fuel was shared by American DIYer and Youtuber Quint Builds. Watch his video to see how he used solar power to pump water up to a tank on his rooftop so that he could later use the energy of that water to generate an electric current.

Water pipe turbines for energy recovery

Take advantage of the water already flowing through your home’s pipes through energy recovery hydropower. This technique uses micro-turbines to turn the water’s pressure into an electric current with a small generator. 

Right now, some urban water systems are employing energy recovery hydropower, but precise pressure management is key in water delivery since too much pressure in the pipelines can lead to water loss. They manage the water pressure by using pressure reduction valves.

Shortly, energy recovery hydropower systems could be revolutionary for micro-hydro power systems made for individual homes.

Biofuel from food waste

When we throw away the food we purchase, we don’t just waste money but energy, too. One way to mitigate these losses is to turn food waste into energy.

There’s a lot of research going into developing systems that can turn food waste into commercial biofuels, but according to Jayanth Sakunaveeti, homeowners can make their own biofuel system for only two dollars. Sakunaveeti, a science enthusiast from India, used a can and PVC pipes to build an airtight container. When there were any food scraps in his home, he’d deposit them into the container to putrefy.

As food waste decomposes, the lipids, phosphates, carbohydrates, and whatever else contained in the food release natural gases such as methane and carbon dioxide. This can be converted into bioethanol, biodiesel, and bio-oil. Jayanth Sakunaveeti produces biogas in his home by collecting and burning the gases from food decomposition.

Tiny Homes

The tiny home trend has been on the up and up in recent years, largely because reducing the size of your home is a surefire way to reduce your energy footprint.

Smaller buildings require less energy and materials to construct, less energy to heat and cool, and less energy to power in general, which saves your wallet as well as carbon emissions.