Hannover. Securing a reliable, affordable and highly efficient energy supply – that's what's driving the steadily growing use of decentralized energy supply technologies by industry, municipal utility companies, the retail sector, real estate companies and residential housing providers. Hence the attraction of ingeniously designed cogeneration (CHP) modules: they can provide the right amount of heat, cooling, steam and compressed air when it's needed, where it's needed.
"Embedded CHP modules offer the twin benefits of being rapidly dispatchable and suitable for baseload supply, so they are vital to the further expansion of renewables," explained Markus Kruse, one of the directors of Wolf Power Systems GmbH, a group of companies that has been in the CHP business for more than 30 years. During that time, Wolf Power Systems has installed over 2,300 modules with capacities ranging from 18 kW to 2 MW. "CHP modules can also be used to even out spikes in system load caused by extreme fluctuations in in-feeds from wind and solar energy. By generating energy (heat and power) at the point of consumption, it is possible to save on grid upgrade costs and avoid the transmission losses that affect large central power stations," Kruse added. It is precisely for these reasons that many energy experts believe CHP will play a key role in successfully bringing the heat, electricity and mobility sectors together to create a climate-friendly, integrated energy system.
Worldwide, the challenges along the way to achieving integrated energy are truly immense. At the same time, there is a wide array of technologies coming onto the market to meet these challenges – as a quick glance at the presentation program for the "Decentralized Energy Supply & Building Energy Technologies" forum in Hall 27 at the upcoming HANNOVER MESSE reveals. Whereas in the past, decentralized CHP units tended to be used more for local heating – especially in Northern Europe – this has now changed somewhat owing to the greater role of renewables in the electricity market. Today, CHP units have an important role to play in feeding power into the grid whenever the sun is not shining and the wind is not blowing. "This is made possible by modern control systems and heat storage technologies," explained Wilhelm Meinhold from Sokratherm GmbH, a CHP specialist that supplies about 100 units in the 50 to 55O kW class annually. Sokratherm's customers include municipal utility companies, hospitals and industrials. At the Energy show at HANNOVER MESSE 2018 it will be showcasing its new GG132 module, which has a combined efficiency of 92.5 percent.
Thorsten Briegel, Head of Product Management at CHP provider Bosch KWK Systeme GmbH, likewise anticipates that decentralized combined heat and power systems will continue to play an important role in the transition to a climate-friendly energy system. "It's not going to be possible without decentralized CHP," he said, noting that CHP technologies will need ongoing technological investment in enhanced dispatchability – the ability to rapidly and precisely ramp output up or down to match changes in demand. One of the big – not to mention extremely urgent – challenges here is to standardize M2M communication between generation units, connected consumers and a steadily growing array of storage units. Achieving smooth, effective M2M communication with the aid of additional, yet-to-be-created interfaces is the key to realizing the full potential of renewable energy.
There are multiple different types of CHP technology available. CHP capacity also varies widely, with output classes ranging from just a few kW right up to several MW. At the lower end of the installed capacity spectrum is Energiewerkstatt Gesellschaft für rationelle Energie mbH & Co. KG, a provider of smaller modules that are suitable for swimming pool complexes, municipal buildings and agricultural use. Energiewerkstatt will be showcasing its ASV 40 module in Hall 27 at this year's show.
Ultimately, it is this variety that makes decentralized energy solutions so powerful. They can be tailored for specific uses and locations to create a range of solutions for trigeneration (combined cooling, heat and power – CCHP), complete boiler houses, high-temperature applications, electric mobility (charging stations), materials drying, and industrial compressed air and steam. The sector is also home to amazing niche providers like HE Energy GmbH, which combines wood gasification technology with thermoelectric generation. Proprietor Horst Erichsen says his company will be unveiling a "world first" at the Energy show: a domestic burner that converts solid biomass (wood) into both heat and power. Not a lot of power, admittedly, but certainly enough to keep the household lights on in remote, off-grid locations.
Wood is still one of the most commonly used biofuels for domestic heating. So commonly used, in fact, that it is easy to overlook the great potential of biomethane. According to the German Energy Agency (dena), Germany could potentially increase its biomethane production tenfold by 2050. That would make biomethane an important source of energy for the heating component of the energy transition. Needless to say, this would have to happen hand in hand with decentralized CHP technology and digitization.