Heat pumps are bankable as subsidy-free solutions in many applications

by pv magazine International

Some heat pump manufacturers are now beginning to demonstrate and promote photovoltaic powered solutions on the market. Normally, however, photovoltaic roof systems and heat pumps are sold separately. They are also installed separately or in a common installation, without a specific energy management system, to maximize self-production of thermal energy with photovoltaic generation.

"While these installations are the standard in residential and commercial buildings today, building retrofits are gaining market share, pulled both by energy efficiency regulations and by voluntary certification schemes," said Roberto Fedrizzi, coordinator of the Sustainable Heating and Cooling Systems Research Group Italian research institute Eurac, in an interview with pv magazine.

Although heat pump systems are now a marketable technology, they are still inherently more expensive than conventional gas boiler systems, which are the market standard. Consequently, the production volumes are not comparable. “Electricity prices are significantly higher – two to four times – than gas prices in most EU member states,” explains Fedrizzi. "That's why there are energy efficiency regulations and public incentives that try to level the playing field for technologies with different industrial maturity levels, thereby facilitating and accelerating the transition from fossil solutions."

Economics of scale

Fedrizzi said that increasing sales leads to lower production costs because economies of scale occur at the component and system level. “In many applications, the heat pump systems are already a bankable solution even without incentives. In newly built tertiary buildings such as offices, hotels and supermarkets, where chillers are needed for air conditioning and cooling in addition to the heat generator, installing a reversible heat pump system is the most effective investment,” he said. In newly built residential buildings, heat pumps coupled with photovoltaic systems are already standard.

“On the one hand, because they contribute greatly to increasing the share of renewable energy used to cover both electrical and thermal loads in a sector where energy efficiency is important to everyone involved, from homeowners up to the decision makers, is seen as a high priority,” he explained. "On the other hand, they make it possible to cover heating and cooling requirements, which as a result of global warming are increasingly being felt to be necessary goods, with a single generation unit."

For newly built residential buildings, the additional costs of a heat pump system are only marginal compared to a conventional gas boiler plus split device solution, while the operating costs are significantly lower. "For example, more than 50 percent of new residential buildings built in Germany in 2020 will be equipped with a heat pump," explained David Moser, coordinator of the photovoltaic energy systems research group at Eurac.

The main obstacles

"The main obstacles to faster adoption are mainly cultural and related to the structure of the hardware store," Fedrizzi continues. "Regarding the first factor, the construction sector tends to be conservative and slow to change." In his view, the heat pump sector is all about generating knowledge and gaining the trust of stakeholders for solutions that don't are conventional.

"As for the second aspect, new construction is just one part of the whole construction market," he said. “While retrofitting heat pumps to buildings is technically viable, it requires modifications to the existing heating system and additional installations compared to simply replacing the existing fossil-fired boiler with a new one; this leads to longer installation times and higher investment costs, which is why builders and homeowners often opt for the simplest and cheapest route, which is clearly far less energy-efficient,” says Eurac researcher Fedrizzi. To address this problem, technology providers and researchers are working to develop and market solutions that are progressively easier to install and operate as building retrofits, while offering homeowners high energy efficiency and additional benefits such as space cooling.

Market size

From a technical point of view, today's heat pumps can cover a large temperature range. "They still work at -20 degrees Celsius and are increasingly providing hot water at 65 degrees Celsius in an efficient manner," says Fedrizzi. "This allows them to be used in a much larger proportion of buildings than a decade ago." According to an EU market report by the European Heat Pump Association for 2021, sales on the European market will exceed 1.6 million units in 2020. The manufacturing industry is pursuing the goal of doubling annual sales by 2030, which could reach around 50 million installed heat pumps by then. The currently dominant technology consists of the air/water heat pump family with about 800,000 units sold in 2020, followed by the reversible air/air units. Air source heat pumps are expected to continue to grow, both at the device and system level, as their lower investment costs and ease of installation will keep them ahead.

The five largest European heat pump markets in 2020 were France with 394,000 products sold, followed by Italy with 232,000 systems, Germany with 140,000, Spain with 127,000 and Sweden with 107,000. The entire EU market grew by around 7 percent in 2020 compared to the previous year. Air/water systems showed the most dynamic growth, both in terms of absolute and relative change. Sales of pure air/water heat pumps increased by 15 percent to 51,000 units and of reversible air/water systems by 25 percent to 47,000 units.

Correct sizing

When asked about the importance of correct sizing of photovoltaic powered heat pumps, the two experts agreed that the system size is not critical as the solutions on the market are photovoltaic systems independent be installed by the heat pump. "Since the power feed into the grid is becoming increasingly unfavorable, the dimensioning and possibly the alignment of the photovoltaic system helps to take into account the daily and seasonal variable electrical loads of the heat pump system and thus self-consumption for cost optimization," explained Moser.

He said additional benefits such as demand-response services being made available to the web are on the horizon, although they haven't existed yet. "If you look at the problem from the heat pump's perspective and consider that heat pump systems always have built-in thermal storage capacity - both in the form of thermal energy storage and in the form of the building mass - controlling the heat pump offers a cost-effective option to to consume electricity under high insolation conditions and to store thermal energy for later use as well as to balance out the fluctuating electricity generation from renewable energies,” says Fedrizzi.

This content is copyrighted and may not be copied. If you want to cooperate with us and use some of our content, please contact: redaktion@pv-magazine.com.