The United Kingdom recently slashed its feed-in tariff, which has led to a rush to solar for people trying to lock in the older, higher tariff. It has been a boon for solar companies and installers, as well as for PassivSystems.

PassivSystems is not a solar company; it is a home energy management company that can also monitor solar panels. The move in solar has allowed the company to add about 200 homes per day onto its platform, according to Colin Calder, CEO of PassivSystems.

“We’re the U.K.’s largest residential PV monitoring system,” said Calder. But PassivSystems hardly sees itself as a solar-focused company. Instead, the technology is meant to tackle the biggest energy users inside the home, primarily the HVAC system and hot water heater.

PassivSystems is one step ahead of many of its competitors with its PV integration system and focus on the hot water heater, which uses more energy than all other appliances combined, according to the U.S. Environmental Protection Agency. 

The company monitors the HVAC and boilers through a hub that then communicates with sensors using ZigBee, although it can also support Wi-Fi and Z-Wave.

The system does not just monitor and control; it also learns the thermal properties of the house and the heat-loss ratio of the water tank. For most U.K. homes, the boiler is fired twice a day, but PassivSystems can reduce that to once a day, said Calder. By integrating weather data and the thermal characteristics of the home, Calder said the intelligent heating controls can save more than 20 percent of total energy use.

The cost of the system is nominal compared to the cost of a PV system, but it is also enticing for utilities that need to reduce peak load. Calder said his company was working with three of the six largest utilities in the U.K.

He would not name specific utilities, but in the competitive U.K. market, British Gas expects that more than half of its business will come from energy services in the coming years, something that Calder’s company can help provide as a white-labeled service.

Between a feed-in tariff and the U.K.’s Green Deal, which will pay for up to $10,000 per home in energy efficiency upgrades, PassivSystems has enough to keep it busy without looking across the pond. “It’s going to be huge for us,” Calder said of the Green Deal. The fragmented U.S. market is also just not that attractive to the company at the time.

PassivSystems has many offerings for the dynamic U.K. market, but it is hardly alone. Other homegrown companies like AlertMe and Onzo are also busy in the home energy management space.

U.S. companies, such as EcoFactor, also have algorithms that use weather data and other information to fine-tune HVAC systems without consumers having to do anything but set their comfort parameters. Although EcoFactor is not working in the U.K., American-based companies Tendril, Opower and Trilliant have projects underway across the pond.

Like other home energy management companies, PassivSystems is taking a multi-tiered approach, working with solar installers, utilities and retailers. So far, Calder said the company’s approach is allowing it to scale to the mass market at a steady clip.

For the Green Deal, PassivSystems is developing a software that would act as a do-it-yourself assessment of the home that energy auditors could use as a front-end sales tool to get customers thinking about how their houses perform and what could be improved.

Other parts of Europe are also attractive, especially Denmark with has high levels of intermittency from renewables. Currently, PassivSystems has not yet fully integrated the PV monitoring to automatically work with HVAC and boiler adjustments, but it will in the future. Not only will the hot water be heated based on when it’s needed and weather data, it could also heat up based on output from the PV panels that are on the home.

PassivSystems will also move into home energy storage in the future. “Our platform allows us to act as an aggregator to help manage a utility’s demand and supply requirements,” said Calder. “We can trade on the balancing market or be part of a new consumer value proposition for the utility.”