On Friday, 14 December, a broad range of representatives from both within and outside the water sector were warmly welcomed at Waterbedrijf Groningen’s Hoogezand production site. The attraction was the roadshow on the theme of Energy organised under the joint research programme, ‘Water in the Circular Economy’ (WiCE), of the Dutch water utilities together with the Flemish De Watergroep utility. The programme included a rich mix of presentations on the role of water in the energy transition, the opportunities open to the water sector and ongoing projects. It became clear what mattered most is taking action, doing; and that this can be greatly helped by learning from each other’s experience.
Water: a key component in the energy transition
The director of Waterbedrijf Groningen, Riksta Zwart, kicked off the event with an inspiring introduction on the origins and path of the huge sustainable energy ambitions. The no-nonsense Groningen mentality was helpful in ‘simply’ getting down to the job at hand, and was incidentally also driven by issues surrounding natural gas extraction. Theo Venema, also of Waterbedrijf Groningen, further explained that about seven years ago they began to seriously develop the water utility’s energy activities with the aim of becoming fossil-energy-free, so that Waterbedrijf Groningen, as a public company, could safeguard the sustainability of water interests in the region. This expressly involves an effort to broaden and strengthen the energy transition.
The Climate Agreement’s goal is to reduce CO2 emissions by 49% in 2030 (compared to 1990 levels). While increasing the sustainability of drinking water production is an obvious part of ‘good house-keeping’, its potential contribution is many times greater outside of the limited context of primary drinking water production. The water sector’s knowledge and experience with groundwater and the subsurface, distribution, materials and pipes, public interests, long-term financial profitability and reliability requirements, are also immensely valuable. Examples here would include the development and increased sustainability of heat networks (WarmthCity Groningen), and the installation and operation of aquifer thermal energy storage (ATES) systems.
Water as a heat and cold source: aquathermal energy
STOWA has recently pointed out that different water sources could meet a large portion of the heat needs in the Netherlands. The potential of surface water is estimated to be 150PJ (40%), of wastewater 42PJ (14%) and of drinking water 5PJ (2%). These water sector sources represent a significant complement to other possible sources, such as geothermal energy and residual heat, from data centres for instance. Since the pipes required to connect heat supply with heat demand are being installed for a period of 40-50 years, one important element to consider is whether the residual heat will remain available over the long term.
Storage crucial for sustainability
In its sustainability effort the Flemish De Watergroep focused first on the importance for energy storage: with the conversion of sustainable electricity – generated for example by floating solar panels on water reservoirs (Evides) or by windmills – into heat and hydrogen, or with the subsurface storage of heat. This subsurface heat storage can play a powerful role in facilitating the development of more robust sustainable heat networks. By ensuring that the heat is stored at a temperature that can be directly used for heating, one avoids the need for energy-consuming heat pumps on the demand side.
The surplus electricity can also be used to produce hydrogen, which can then be temporarily stored in high-pressure tanks. Hydrogen can play a key future role in promoting sustainable mobility. Stefan Holthausen, of Holthausen Clean Technology in Hoogezand, showed that the range of electric cars equipped with hydrogen units can be hugely extended and, moreover, that the charge time is being cut to the time it takes for a regular tank fill-up. Once sustainable solar and wind energy are converted into hydrogen, and the hydrogen infrastructure is further developed, an enormous impetus will be given to driving on ‘green’ hydrogen.
Making sustainable energy collectively available calls for collaboration and strong governance
The combination of sustainable energy from various sources – for example, electricity generated locally or at wind parks on the North Sea or beyond – together with the different conversion and storage options, allows for flexible solutions that can be tailored to each specific situation. At the same time, this increases the need for strong collaboration between the different stakeholders and sectors, and for clear governance. Water managers, such as water utilities and Water Authorities, are clearly aware of their public task. The question is what role they want and can play, and how. Waternet’s experience in Amsterdam, for instance, makes it clear that collective systems are needed, and that these must be developed on the basis of serving the public interest, without presenting a threat to the market.