Some 38% of greenhouse gas emissions emanate from residential housing, specifically heating and cooling systems. Given the goal of ‘net-zero’ carbon emissions by 2050, new approaches have emerged to achieve that target. Some of the solutions currently being evaluated include the use of hydrogen as a replacement fuel, to store electricity from solar or wind power, or in fuel cells that use an electrochemical process combining hydrogen and oxygen to produce electrical energy and water.
Hydrogen is the most abundant element in the universe, although pure hydrogen is rare on earth. It can be extracted from water (electrolysis), Alternatively, it can be extracted from natural gas using carbon capture technology to prevent carbon, a by-product, from escaping into the air.
Modern terrace houses
Whether hydrogen is burned for heat or passed through a fuel cell to make electricity, the only byproduct is chemically pure water. When combined with renewable energies like solar and wind power, hydrogen can be used to store energy as an alternative to batteries; unlike batteries, hydrogen gas can be stored indefinitely.
FutureGrid operates three modern terrace houses with gardens in the remote hills of Cumbria
Like natural gas, hydrogen is odorless. The distinctive smell currently added to natural gas could also be added to hydrogen to ensure residents quickly notice a leak. In the United Kingdom, FutureGrid operates three modern terrace houses with gardens in the remote hills of Cumbria. The houses provide a preview of a world where hydrogen has taken the place of natural gas.
Yellow polyethylene pipes
Engineers are testing how Britain’s natural gas pipe infrastructure can be converted from transporting fossil-fuel gas to handling hydrogen. Heating of British homes accounts for about 15% of carbon emissions, which would be eliminated with a transition to hydrogen. Hydrogen is more combustible than traditional natural gas, and its smaller molecules make it more likely to leak.
There is a historical precedent for the transition in the United Kingdom. During the 1960s and 1970s, the gas industry converted from town gas (a byproduct of the distillation of coal and oil) to natural gas (mostly methane), which was discovered in the North Sea. The transition to a pipe system that can accommodate hydrogen has arguably already begun in the United Kingdom, where the gas industry is using yellow polyethylene pipes (which do not interact with hydrogen) to replace the metal pipes (prone to become brittle when exposed to hydrogen) in the country’s iron mains network.
High-Volume technology
Worcester Bosch has developed a hydrogen-fired boiler that could replace natural gas boilers
An advantage of hydrogen is that the transition would be undetectable to consumers, who could continue to use boilers to heat their houses, although the fuel would be hydrogen rather than natural gas.
Worcester Bosch has developed a hydrogen-fired boiler that could replace natural gas boilers, but they use a hydrogen blend – 20% hydrogen and 80% natural gas. In the future, converting to all hydrogen would require an hour-long service call and only involve changing a couple of components such as the burner. Hydrogen boilers are currently a niche market; however, a regulatory change mandating their installation could make them a high-volume technology, just as natural gas boilers are today, according to the company.
Heat pump technology
Skeptics point to the cost of converting a country’s underground gas pipelines to hydrogen. Others suggest that a transition to energy-efficient electric heat pump technology would be simpler, and in fact is already underway. In the heat pump scenario, hydrogen could be used in a fuel cell or to store energy (from solar or wind power) in lieu of batteries.
Skeptics point to the cost of converting a country’s underground gas pipelines to hydrogen
The Hydrogen House in Hopewell, N.J., has been converted to run exclusively on solar and hydrogen power. Inventor Mike Strizki converted the home with a grant from the New Jersey Board of Public Utilities and using his own personal funds. It is the first solar-hydrogen residence in North America and operates completely off the grid. The only emissions are chemically pure water and medical-grade oxygen.
Medical-Grade oxygen
Features include a 40kw solar installation, 20kw backup power, an electrolyzer to generate hydrogen, and a hydrogen fuel cell. The home was designed to allow for the expansion of an electric and/or hydrogen refueling station. The plan is to transform the house into an interactive educational attraction with hands-on demonstrations related to clean and renewable energy.
The Vitovalor 300P is a fuel cell heating appliance, made by German manufacturer Viessmann, that uses the principle of cogeneration to generate both power and heat. To do so, the fuel cell requires oxygen and hydrogen (obtained from natural gas in an earlier process). The generation of heat and power is based on an electrochemical reaction between the two elements, also called cold combustion.