Low-cost installation and government support for net-zero energy homes are creating the perfect conditions for rooftop PV in the Netherlands, according to experts.
The low-energy housing collective Stroomversnelling, for example, has already brokered a deal to create 111,000 net-zero-energy homes for six Dutch housing associations by 2020.
Thereafter the organisation expects to refurbish up to 50,000 homes a year, as well as installing PV as standard on all new-build construction. Stroomversnelling’s manager of European markets, Ron van Erck, said it was possible to cut rooftop PV system costs by 50% simply by using solar panels to replace standard roofing materials.
“More than half the cost [of standard rooftop PV] is in things like racking,” he said, which is not needed if panels are used as a roof covering. “And you don’t need roof tiles as well.”The new roofs can be installed in a week and come with a 30-year guarantee.
When deployed alongside thermal recovery measures and low-electricity-consumption devices, they can help cut effective annual energy use to almost nothing.
Stroomversnelling hopes to fund the installations by replacing residents’ electricity bills with a fixed monthly fee, payable for the lifetime of the rooftop guarantee, which includes a 5% return for the construction company.
The formula will enable homeowners to cut their household carbon emissions and guard against future electricity rate rises. It will also eliminate a significant barrier to residential PV installation: the fear that homeowners might have of paying upfront for solar and then having to sell their property before they have fully recouped their investment.
Gerard de Leede, chief technology officer at the property developer Heijmans, said the Dutch government’s net-zero-energy homes programme was just one of three factors boosting the importance of PV for the construction industry.
“We have regulation in this market, based on net metering, that makes PV a viable product at this time,” he said. “And the cheapest way of meeting certain energy performance coefficient values is through PV panels.”
The Netherlands is also perfect for these kinds of installations because it has large amounts of public housing based on standardised building processes. “There is a huge number of houses you can renovate,” de Leede said.
This is just as well, because Stroomversnelling’s van Erck said the Netherlands would need to convert around 60% of its total housing estate to net-zero-energy homes by 2050 in order to meet the nation’s carbon reduction targets. And since the opportunity for a house renovation only comes around once a decade or so, there are limited openings for construction companies to deploy full-roof PV. This makes it imperative for developers to embrace solar now.
“In 30 years this stock needs to be converted,” said van Erck.