SPECIAL ENERGY

Storing solar and thermal energy in your home

21 Sep 2022 | Headlines

If Switzerland is to rely more and more on renewable energies, storage technologies will play a decisive role. Research and industry are working hard to make the corresponding technologies more efficient and simpler.

Solar energy will play a major role in achieving these objectives. Unfortunately, it doesn't always produce electricity precisely when it's needed. Life goes on at night and on short winter days, when the performance of solar installations is limited. It is therefore vital to compensate for this imbalance between production and requirements to avoid shortages in winter - and this also applies to private homes.

Solar energy: maximizing self-consumption

Storage systems combined with solar

Solar power systems should above all help you to increase your own consumption - in other words, to use the solar energy you produce yourself, if possible. Self-consumption is always a decisive argument for the profitability of a photovoltaic system: the more electricity you consume yourself, the more profitable the investment - not least because the proportion of electricity purchased from the grid is reduced. Batteries help to reduce this share. According to Swissolar, the association of solar energy professionals, they can increase the proportion of self-consumption by up to 90% - especially with high-performance batteries integrated into an intelligent energy management system, where they communicate efficiently with the photovoltaic system, heat pump and household appliances. In some cases, electric car batteries can also be used as intermediate storage units, thanks to their bi-directional charging capabilities. Storage units thus limit dependence on the public electricity grid. Larger units can even help to make you completely independent of the grid, and protect you from potential shortages. Currently, one in five photovoltaic systems is installed with a battery, and this share is set to rise. Lower prices for these technologies are stimulating demand. Before replacing your oil or gas heating system, it's a good idea to think about a suitable storage unit. That way, you'll be well equipped for the future.

What's the point of home batteries?

Not all energy professionals agree on the conditions under which the use of domestic batteries makes sense. Admittedly, they can help to use solar power more locally, and thus increase clean consumption. “But from an ecological point of view, it doesn't make sense to install a battery in every home,” argues Ludger Fischer. Economically speaking too, the use of batteries in private homes has its limits. Often, the costs cannot be amortized, because prices are too high, and electricity tariffs and feed-in tariffs too low. It makes more sense to make immediate use of surplus production from photovoltaic systems, for example by generating heat. In Switzerland, lithium-ion batteries are used almost exclusively to store solar-generated electricity.

How research is making batteries more sustainable

The industry is currently developing multifunctional batteries. This category includes bi-directional automotive batteries that can also supply electricity to the home. By diversifying possible uses, ecological and economic drawbacks are reduced. This principle also applies to older car batteries, which often still have sufficient capacity to be used in the home. Neighbouring homeowners can also consider acquiring a battery together to share the solar electricity they produce - a model known as Regroupement dans le cadre de la consommation propre (RCP).

How to cover your heating needs while respecting

the environment

The Swiss need a lot of heat: heating and hot water still account for at least 40% of total energy consumption in Switzerland. In households, this share is even twice as high. It is therefore in our interest to store renewable energies during days of intense sunshine.

Buffer tank and water heater

heat pump water heaters

A buffer storage tank for heating, a thermal storage tank for drinking water or a mixed storage tank (also known as a sanitary storage tank) prevents the heat pump from switching on at the slightest immediate need for hot water or heat in the evening or on gloomy days. Most hot water tanks are inexpensive, and therefore profitable. Get professional advice before you buy, and check that the various components fit together properly.

Heat pump water heaters are very widespread, and are the modern counterpart of the electric water heater. Many models can be combined with photovoltaic systems, significantly lowering running costs for hot water.

Seasonal heat accumulators

and heat pumps

Seasonal heat accumulators are ideal for storing heat over long periods. They generally use water as the storage medium. Low-temperature accumulators, geothermal accumulators, above-ground thermal storage tanks, aquifer storage and, exceptionally, ice accumulators are all possible solutions. Water releases large quantities of energy during the phase transition from liquid to solid state. The heat generated during ice formation can therefore be used for heating.

Heat pumps also help conserve excess energy. They convert the electricity produced into useful heat and, thanks to storage, the thermal energy can even be used during phases when the photovoltaic system is not producing electricity.

François Berset

with ©SuisseEnergie

About Cerise Immobilier gérance et courtage, real estate agency in Villars-sur-Ollon

Cerise Immobilier gérance et courtage is a real estate agency located in Villars-sur-Ollon in the canton of Vaud, Switzerland. We offer services in sales, purchases, rentals, PPE management, property valuations and tax and legal advice. We cover the Chablais region of Vaud, including the communes of Ollon, Gryon, Bex, Aigle, Les Diablerêts, Chessel, Leysin, Lavey, Noville, Roche, Yvorne and Villeuneuve.

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