We are moving towards a natural gas-free future. “Heat and Cold Storage” (ATES) seems to be one of the answers to the demand for climate-neutral and sustainable entrepreneurship. Recycling your own energy, as it were. Because the use of a cooling system, for example, generates heat ‘at the back’, but how do you use it as a company for your own use? How do you store that energy? How do you save with that?
“ATES” is an open soil energy system. Energy from the building and / or the systems is stored in the ground and recovered in a water-containing sand and / or pebble layer by means of pumps. ” Many companies will have a period of heat or cooling demand over a day or throughout the year, and a period of surplus later on. In those cases it is of course useful to buffer the heat and cold. Long-term storage in the soil with a warm and a cold ‘source’ is a useful solution. ” How does a ATES work? “In winter, the building is heated with a heat pump that extracts heat from the groundwater pumped up from the warm source. The groundwater cools down and is pumped back into the cold source. In the summer, this cooled water is pumped up again and used as passive cooling. The water heated by this is returned to the warm source. The cycle has thus been completed. ” The specific composition of the strata in the soil of West Friesland and the low underground current keep water well in the wells or wells at a depth of about 80-100 meters and the water at a constant temperature.
In West Friesland, a number of companies have been far ahead of their time and switched to ATES years ago, in collaboration with Polytechniek BV “Installer from A to Z” in Hem. Such as De Wit Bloembollen in Bovenkarspel. Director Arjan Rood explains: “In 2007, the need arose to make our company ‘future-proof’, including in the field of energy supply. In a nursery / hatchery this is an important aspect anyway, but at that time a shortage of gas was already imminent and we expected gas prices to rise accordingly. The innovation of that time included pump cooling and heat and cold storage: that’s what we dived into. Our relationship with Polytechniek BV went back decades, so together with them and our advisers we researched, mapped out and calculated options. In 2008 our current ATES installation became a fact. The financial investment was indeed a barrier, but the – at that time still applicable – government subsidy, as well as the impending high gas price, made us decide to use this innovative system. We now have our own cold and warm source at a depth of about 100 meters: our own energy storage. As soon as we need the heat or cold again, it is retrieved with the specific pumps and used immediately. Because no matter how unimaginable: there has been virtually no change in temperature. ” Sounds pretty straightforward: was it that simple? “Well no. Now I think we were a little too far ahead of our time. Knowledge and expertise in the field of sustainable energy, the use of residual heat and therefore also the thermal storage system, was still in its infancy. This knowledge and expertise has gradually grown and we have been able to implement more improvements and more savings.
Long story short: we realized a 32% reduced gas consumption in 2018! And despite the fact that the power consumption has increased by 13%, we are talking about a very serious financial saving! We are making that savings even more serious this year with the installation of 1,800 solar panels for sustainable power generation. Because sustainable cultivation is ‘hot’! ”
And another West Frisian precursor: Flexibol in Hem. According to director Pieter Langedijk and manager Sam Koopman: “our unique selling point is that we are not the largest, but we are the greenest”. A West Frisian company that is already completely free of gas! They have been self-sufficient since 2012 with two of their own wind turbines, 1,100 solar panels and a thermal storage system. “We harvest our own heat. We do not need much cooling, but all the more need stable heat. We achieve this with our own resources and the source and heat pumps from the WKO of Polytechniek BV. We consume what we need and supply the remainder back to the grid, so we are now actually also an energy producer. ”
Sustainable entrepreneurship has long been of paramount importance to Flexibol and they were looking for new ways to use their own (residual) energy for their offices and apartments. During the construction of a new storage hall in 2011, they decided to switch to a thermal storage installation. Flexibol also found a partner in Polytechniek BV for this. When asked if they have any advice for the companies that are currently considering the switch to ATES, Pieter says: “Even though we were sometimes puzzled by all that innovativeness, Polytechniek has always helped us. But now I say: keep it simple; don’t make your system too complicated.
A ATES is an intelligent, but dynamic system: make sure you have some affinity with technology in-house. For example, understand that what you adjust on the warm side in the system has an effect on the cold side. ” So balancing with energy? Natural gas is being phased out, as technical advisor Rob van Buiten of Polytechniek BV also points out: “heat-cold storage is the present and the future. But instead of blowing excess heat (ie energy) into the air, for example, we have to juggle with that energy. ” And that juggling is not done in the air, but in the bottom. And that soil must remain ‘in balance’. Very simple: whatever you put in, you eventually have to take out again. All this is accompanied by permits, certifications and necessary soil surveys. “And that is also part of our package.” And the future? “Polytechniek now has more than 45 years of experience in advice, design, installation and maintenance in the field of all types of technical and innovative installations, both in non-residential construction and in the agricultural and industrial sector. We currently have five applications for a thermal storage system on the calculation table, but we are also conducting research in West Friesland into, for example, high-temperature storage in the soil. We continue to innovate. ”