Hydrogen and RNG gas blends are being touted as a way to reduce emissions from burning gas for heat. Are they an effective strategy or waste of time and money?
IN BRITISH COLUMBIA, the consumption of natural gas is 165 percent larger than the consumption of electricity. If you take transportation out of the equation, fossil gas and biofuels account for over 70 percent of BC’s energy use—most of it for heating. Reducing heating emissions will, therefore, be crucial to the success of BC’s climate plan. BC is asking gas utilities to halve their GHG emissions by 2030—but is still expanding gas distribution, hooking up new homes and businesses, and subsidizing fracking and LNG.
This article examines a Fortis proposal to blend (by volume) 15 percent Renewable Natural Gas (RNG) and 20 percent blue hydrogen (BH2) into their existing gas grid. Gas blending would allow the existing gas distribution and end-use appliances to remain in use, but significant new infrastructure would be required. A schematic overview of the proposal is shown in the following graphic:
The potential for successful emission reductions does exist. For example, climate progress could be made if efficiency and electrification eliminate the majority of all BC gas heating loads, and more RNG is collected from existing methane waste sources, and if the hydrogen used is made from water, rather than natural gas.
On the other hand, gas blending could prove to be a climate dead end—a gas company growth strategy that delays electrification and prolongs methane and CO2 emissions.
Are provincial government, Utilities Commission and Fortis plans for combustion compatible with CleanBC climate goals? The answers to the following questions could provide an indication.
Should RNG be used in this way?
Capturing RNG from organic waste has the very real climate advantage of reducing atmospheric methane. Fortis has been adding RNG to its grid for some years now. As such, it seems an attractive option.
The available volume would have to be increased from landfill, agricultural, forestry and industrial wastes. Collecting the RNG from these far-flung sources would involve new infrastructure, and be much more labour intensive than the existing collection of natural gas. Methane leakage would also have to be eliminated.
Energy cost adjustments would be required. If natural gas subsidies were eliminated, and the full carbon price of $170 per tonne was applied, RNG could be more cost competitive with natural gas. This, however, would also make electrical heat a more attractive option to gas.
Considering such factors, it appears that RNG would be a better climate solution for decarbonizing shipping and other hard-to-abate sectors, rather than for heating loads that can be electrified.
Should hydrogen be used in this way?
Blending 20 percent green hydrogen with natural gas reduces GHGs by 7 percent at best. This is because, among other issues, pure hydrogen has one-third the energy per unit volume of natural gas.
Fortis, being a gas utility, is probably hoping to use blue hydrogen made from natural gas feedstock. This would introduce efficiency losses through methane extraction, hydrogen production, Carbon Capture and Storage (CCS), and gas-powered equipment. The following is a very high-level summary of the main hydrogen colours:
As with RNG, hydrogen is expensive, in low supply, and would be a more effective climate measure if used for the decarbonization of air travel, steel and fertilizer manufacturing, etcetera, rather than for heating.
What climate impact can we expect from the proposed gas blending?
Reducing methane emissions is our best tool to keep global warming below 1.5C in the crucial next 8 years. Gas blending would put extra natural gas and RNG in play—and open the door to more potential fugitive methane emissions.
If we make some very generous assumptions—such as no lost opportunity for other hard-to-abate sectors, no added methane leakage, no energy penalty for transporting hydrogen, and no gas-fired processing equipment—then the proposed gas blending has the theoretical potential to reduce affected gas heating GHGs by 24 percent.
This, unfortunately, is far from BC’s net 100 percent reduction goal for 2050.
If gas blending is seen as a stepping stone to pure hydrogen—moving from virtually no climate benefit over the first number of years, to Net Zero 2050—then existing pipes, compressors, burners and motors will need to be replaced for use with pure hydrogen. When do the substantial cost and safety concerns of this transformation turn up on the balance sheet? How much extra gas will have been leaked and burned in the meantime?
From a climate science perspective, the GHG improvements of this gas blending proposal appear to be “too little; too late” when compared to electrification.
What are the human health concerns of continued (or expanded) combustion?
Oxides of nitrogen and ozone from natural gas combustion already cause significant indoor air quality problems, contributing to juvenile asthma, for example.
Burning hydrogen can be worse than natural gas in this regard. Industrial furnaces and boilers that burn hydrogen or hydrogen-rich mixtures may be fitted with selective catalytic reduction units to reduce NOx, but that option does not exist for residential/commercial furnaces and stoves.
Are there safety concerns?
Hydrogen leaks more than natural gas due to its low density and high diffusivity. It has a wide range of flammable concentrations in air, and lower ignition energy than natural gas. It can ignite easily. It also burns with a nearly invisible flame, especially in daylight.
Natural gas stenching agents, such as mercaptans, are not compatible with hydrogen. Will this create problems for gas leak detection?
CO2 pipeline safety is a concern associated with sequestration. About 100 people already die globally each year from CO2 accidents.
Are there other issues to consider?
BC already expects a massive increase in fracking for LNG. What additional water/air pollution, biodiversity, Indigenous reconciliation, earthquake and tailing pond cleanup impacts and costs can be expected as a result of the proposed gas blending?
Is there an alternative?
The well-understood, proven, safe and clean alternative to gas heat is electric heat. Direct use of renewable electricity for resistance heating is much more efficient than manufacturing hydrogen, and then converting it into heat. Heat pumps for space and water heating are better yet—providing 3 kWh of heat for every kWh of electricity input.
BC Hydro’s new Electrification Plan (September 2021) would contribute only 4 percent to BC’s annual GHG emissions reduction target for 2030. Dylan Heerema, senior policy advisor for Ecotrust Canada, has calculated that if BC’s Electrification Plan succeeds, it will reduce BC’s total emissions by only 1.3 percent.
This won’t get BC to its climate targets. Efficiency and electrification need the type of political drive and ambition that went into launching BC’s LNG industry.
Reaching BC’s climate pledge will involve some degree of disruption and cost. For example, a commitment to electrification comes with the need for a larger power system, but the size of the change can be controlled by pre-work to reduce heating demand. If Canada needed to double its electricity generation, a recent report by the Pembina Institute argues that sharing power between the provinces via integrated national grid inter-ties would help immensely. Such a grid would optimize the location and types of new power and storage sources; require less overall backup power reserves; save both capital and operating expenditures; and produce more opportunities for storing and reselling excess US power. Perhaps most important, it would also result in rapid climate action while avoiding the creation of new technologies and regulations.
Given the urgency of addressing the 1.5C global warming goal by 2030, and the lead time required to research, test, regulate and scale carbon capture and storage, blue hydrogen, and new RNG sources, etc, gas blending does not appear to be a reason to maintain or expand combustion heat.
Rather than create uncertainty about electrifying heating and cooking, it is time to stop hooking up new BC homes and businesses to gas.
Bob Landell is an energy management consultant and climate-concerned grandfather living in Victoria, BC.