At the Birmingham International railway station in the heart of England, millions of passengers every year make their way through a vast concourse on their way to and from their trains. That concourse includes restaurants, cafés, shops, public seating areas, and restrooms. It is now getting an energy upgrade thanks to a pilot program designed to test the viability of solar thermal for providing the hot water the rail station needs to operate every day.
The Birmingham pilot is a little bit different in that initial plans don’t call for the solar thermal system to be the exclusive provider of hot water to the station and its tenants. Instead, the solar thermal system will preheat water coming in from the city’s main supply before sending it on to the rail station’s dual gas-fired boilers that will finish the job.
That said, a successful test of the system may lead engineers to switch exclusively to solar thermal and use the gas fired boilers only as a supplement when necessary. But that decision is still some time in the future. For now, they want to see how well solar thermal works for the purposes they have intended.
Using Evacuated Tube Solar Collector Panels
Like all other highly efficient solar thermal systems, the star of the show in Birmingham are the ten evacuated tube solar collectors mounted on the rail station’s roof. These collectors absorb solar energy from ultraviolet rays, then transfer that energy to a thermal liquid. The benefit of this system is efficiency. An evacuated tube loses very little energy in the transfer process, so almost all the energy absorbed is sent into the system.
The heated thermal liquid is forwarded to a heat exchanger where heat energy is extracted before returning to the collector panel. Extracted heat can either be stored or used immediately to heat water. In principle, the system is rather simple.
Engineers in Birmingham have decided to use their system to preheat a mains water supply that enters the property at roughly 10°F. Water temperature should be as high as 95° before leaving the solar thermal system on the way to the gas-fired boilers. They will increase the input temperature of the water to 140°. But here’s the thing: the solar thermal system should be able to push the main water to 140° or higher during the warm summer months all by itself, eliminating the gas-fired boilers.
Throughout the pilot program, a heat meter will keep track of the system and analyze its benefits and financial savings based on the UK’s Renewable Heat Incentive program. If the system proves successful – and there’s no reason to believe it will not – we can easily see similar systems installed at rail stations around the country.
Solar Thermal Is Where It’s At
For years, our focus for solar energy has been on systems that convert sunlight directly into electricity. While these systems have proven their worth in some areas, they have not proven to be as efficient and cost-effective as solar thermal for space heat and hot water. In short, solar thermal is where it’s at.
The Birmingham International rail station is on the verge of learning how beneficial solar thermal can actually be. But they are by no means the first. Here at Solar America Solutions, we have already been part of numerous installations at all kinds of commercial and government buildings. Throughout the U.S., countless property owners have come to realize that the best way to provide space heat and hot water using renewable energy is to go solar thermal.
- Modern Building Services – http://www.modbs.co.uk/news/fullstory.php/aid/16265/Railway_station_trials_solar-thermal_for_DHW_.html