Green gas energy
Run your gas furnace without contributing to climate change
Green gas energy is similar to green electricity in that it consists of natural gas produced from a renewable source. This means that the natural gas you burn has a net zero impact on climate change. Sure, this 'biomethane' gas releases CO2 which is a greenhouse gas. But (in theory at least), that impact is offset, either by the fact that the gas would have been burnt anyway without being used - and so wasted - or that the gas would have been released into the environment without burning it, which is far worse for climate change. Let's look at the different scenarios and how they really affect your contribution to climate change.
First of all, full disclosure: I am a green gas energy customer, as well as a green electricity customer, even though I recognize that buying green energy doesn't necessarily make the world a better place. I pay a premium to Bullfrog Power, a Canadian supplier of green electricity and green gas energy, while still receiving my electricity from the regular power grid and my natural gas from my local natural gas company. But Bullfrog monitors my usage and ensures that enough green, renewable electricity is pumped into the grid to offset my electricity consumption, and now it pumps enough biomethane into the natural gas company pipes to offset the natural gas used by my furnace and hot water heater.
Let's cover the sources of green gas energy, how you can sign up, and whether it really is an environmentally sensible solution to buy green gas.
Topics covered here:
- Sources of green gas
- How does signup and billing work for green gas
- Does buying green gas really make a difference?
Sources of green gas
Natural gas (methane, or CH4) is found in petroleum deposits, and as clathrates (frozen methane) deep in artic oceans. These forms of natural gas can be considered fossil fuels and so they are definitely not green sources of natural gas. Almost everyone who buys natural gas gets the fossil fuel variety.
When methane is burned, it is combined with oxygen and converted into water and carbon dioxide. The exact formula - if my high school chemistry memory serves me - is: CH4 + 2(02) = CO2 + 2(H2O) + E (where E is energy released as heat and light).
Both the CO2 and the water vapor (H2O) released during this process are greenhouse gases. Water vapor is the most common greenhouse gas, but is usually not factored into discussions about burning fossil fuels, while CO2 is considered the villain in fossil fuel combustion, and the greenhouse effect of various gases in the atmosphere is generally described in terms of CO2 equivalents. It turns out that methane is a substantially more potent greenhouse gas than CO2, with a volume of uncombusted methane in the atmosphere having roughly 30 times more of a climate change impact than an equivalent volume of CO2.
When organic matter decays, the bacteria that break it down release methane, along with other gases. In fact, belching cattle are a major contributor to anthropogenic (human-created) greenhouse gases because the bacteria in their gut that help break down cellulose into digestible starches and sugars release methane in the process. Organic decay doesn't just happen in cows' guts. The steady rise in arctic air temperatures over the last few decades has resulted in significant amounts of permafrost melting, and the organic matter in this permafrost, once melted, begins to decay and release methane as a result. It probably doesn't make sense to call this green gas energy - even assuming we could capture the methane as it is produced by the decay - because if we could just keep the permafrost frozen, we wouldn't have a methane problem to begin with. Instead, the melting permafrost creates a positive feedback cycle, where methane produced by the melting permafrost warms the atmosphere, resulting in ever more melting permafrost.
But capturing the methane from belching cows would be a true source of green gas energy, assuming that gas is being produced anyhow by agricultural practices. The same is true of capturing the biomethane from rotting cow manure or agricultural crop wastes. Other sources of biomethane include sewage treatment facilities - where back in my childhood you often saw flares or gas plumes burning off the methane being released during decomposition of the sewage - and landfills, where garbage buried underground can continue to decay and release methane even decades after the landfill is capped.
In recent years a number of businesses have found ways to capture the green gas energy in cattle operations, sewage treatment plants and landfills. For example, there are cattle operations in Texas producing enough methane to power electricity generation for 11,000 homes. (The ratio is slightly less than one cow per home.) Some smaller cattle operations can power and heat their barns using biomethane from the cows' manure, while larger operations earn a major additional source of income by selling the green gas energy to power utilities for use in electricity generation.
Landfills and sewage treatment plants, meanwhile, have moved more and more towards capturing the methane released by their operations, and instead of just burning it off in flares, using it to generate electricity onsite that then gets fed into the grid.
When you buy green gas energy what you are really doing is buying a share of the natural gas produced by such a facility - typically a landfill or sewage treatment plant - and pledging the company you contract with to contribute an amount of that facility's green gas production into the gas company distribution system equivalent to the amount you draw out. As such your home is not directly burning green gas, but by purchasing green gas energy you are helping create more demand for it. In theory this should drive green gas prices up to motivate more landfill operators, sewage treatment operators, and cattle operations to capture their methane and feed it into the gas distribution system, since the premium we're willing to pay will make it profitable for them to do so.
How does signup and billing work for green gas
As with green electricity, there are typically two ways you can sign up for green gas energy. First, you can purchase green gas certificates for a specified amount of biomethane - specified either by volume or by kilowatt hours of equivalent energy. When you purchase green gas certificates you are basically paying the producer a premium in exchange for that producer retiring any carbon credits they might otherwise obtain from the biomethane production. In theory, you could buy green gas energy certificates from an agency in Britain, while consuming natural gas from fossil sources in Abu Dhabi, and your green gas purchase would offset the CO2 emissions of your natural gas consumption.
The second way to buy green gas energy is to contract, as I do, with a green energy supplier, which gets a monthly reading from your local gas utility meter, and bills you for the difference in price between fossil sourced methane and biomethane.
Let's look at each of these two approaches to buying green gas, and what they really mean to you as a consumer and to the environment we all share.
Green gas certificates: Imagine that you are a landfill operator. You could just burn off your methane in a gas flare and release CO2 into the atmosphere without converting the heat into useful work (such as powering a generator or heating a home or office). This would be bad for climate change. Even worse, you could just release the methane into the atmosphere. If you do convert the heat into useful work, such as by running a generator or feeding the gas into a natural gas distribution network, you can get paid for the energy you contribute to the grid.
But you can do even better, because in many jurisdictions (unfortunately, not in most of the US or Canada), industries are mandated to reduce their CO2 emissions, and one way they can do this is to buy carbon credits, which allow one company to release CO2 in exchange for another company that previously did release CO2 no longer doing so (or for capturing CO2, for example by planting trees). The company producing X tons of CO2 buys a carbon credit for X tons of CO2 emissions from another company that is either avoiding the release of X tons of CO2, or capturing an equivalent amount through tree planting or other carbon capture methods.
So as a landfill or sewage treatment operation, you can not only sell your green gas energy to the regular distribution network, but you can sell the carbon credits for it to a company - anywhere in the world - that needs or wants to buy carbon credits to offset its own emissions.
The cost of carbon credits is set by market demand. The more expensive it is to buy carbon credits, the more incentive polluters trying or required to offset their emissions have to find ways to reduce their own emissions instead of buying the carbon credits. That is where green gas certificates can help. When you buy a green gas certificate, the producer of that green gas is basically committing to retire the carbon credits related to that green gas energy so that they cannot be sold to offset CO2 emissions somewhere else.
Buying green gas certificates is relatively easy as you simply hand over money for a given amount of biomethane to the company producing the biomethane, or to a broker acting on their behalf. You could, for example, look over your natural gas bill for the last 12 months and buy enough green gas certificates to cover that amount of consumption. You'll still be emitting CO2 by burning your regular natural gas, but you'll be helping drive up the price of carbon credits, which will encourage companies to find ways to cut their own emissions instead of trying to buy their way out of cutting emissions.
I have never bought green gas certificates myself, but I have bought green energy certificates. The trouble I have with these certificates is that people tend to buy them once, and feel great about the action, and then never buy them again. You need to actively remind yourself to renew, and you need to measure your natural gas consumption yourself in order to figure out what amount of green gas energy to pay for on your next certificate.
Green gas suppliers: The second way of buying green gas energy is, I believe, better for the environment and easier to manage from the consumer's point of view. I don't need to pay a big chunk of cash up front to buy a year's worth of green gas certificates. Instead, I get a monthly bill, that is in addition to my regular natural gas bill, and that is directly tied to my consumption. This means I am paying more for natural gas than my neighbors who are not buying green gas energy, and my extra payments are helping make it more profitable for companies to produce green gas instead of flaring it off or releasing it as methane.
One advantage of using a green gas supplier is that payments are spread out over the year and you don't have to remember to renew, or pay a huge chunk of money once a year. As well, your payments are directly tied to your usage, and when you see your green gas bill shoot up (along with your regular utility gas bill) you'll have an incentive to cut your home energy use - using many of the tips provided elsewhere on this website.
When looking for a green gas supplier, make sure you choose one that explicitly states that any renewable energy certificates or carbon credits relating to the green gas you are buying will be retired, and not sold. This is important because if a company is simultaneously charging you a premium for putting green gas into the system on your behalf, and charging a CO2 emitter for the carbon credits it has at its disposal for producing the green gas energy, they are double dipping and your payment isn't really helping reduce worldwide greenhouse gas emissions.
My green gas supplier allows me to sign up for 100% green gas energy, or a set amount per month, or a percentage of the total. In other words, if I can't afford to pay the green gas premium on all my natural gas, I can at least get a certain percentage or amount of green gas added to the distribution system on my behalf, while continuing to rely on fossil sources for the rest.
Does buying green gas really make a difference
I can see arguments on both sides of this question. I know, for example, that many of the carbon credits currently sold on the worldwide carbon market may not be making any difference other than to line the pockets of the companies selling the credits. For example, a forestry company in Ontario, which is mandated by law to replant any forest lands it harvests, might earn carbon credits by selling the fact that is replanting the forests it chopped down. But the fact is that the company was going to plant those trees with or without the carbon credits. Similarly, one could argue that the Beare Valley landfill near my part of Toronto was already producing electricity from its methane emissions, and so instead pumping that biomethane into the gas distribution system and selling it as green gas isn't going to reduce overall CO2 emissions.
But the idea is to create a stronger market for green gas energy, in order to motivate more companies to produce it. For example, cattle farmers in Canada have really not embraced the biomethane movement because there are few government incentives to do so, and they don't see a profit in it otherwise. But a strong demand from consumers and businesses for green gas could make it increasingly profitable for them to produce biomethane.
I've seen this phenomenon at work with my green electricity supplier for years, ever since I first signed up. Every quarter they send out a newsletter, and in it there are always announcements about how many new customers have signed up, as well as announcements about what new deals they have inked with wind and small scale hydro suppliers. In other words, the demand my green energy supplier is creating by offering green electricity and green gas for sale is encouraging companies to start producing these clean forms of energy.
It's true that the methane burning inside my furnace tonight probably came from a fossil source. In fact the landfill my green gas is sourced from is several hundred miles east of me in Quebec, while I am pretty sure the general movement of natural gas through Canada's gas pipeline systems is in a southeasterly direction (flowing from the west and northwest towards Ontario, Quebec and the Maritimes) so it is extremely unlikely any of that landfill's biomethane is burning in my house. But I am helping reward that landfill for contributing its gas to the green gas supply, and I am sure that, as more and more people sign up with green gas suppliers or buy green gas certificates, we will see more and more companies jumping at the chance to convert their waste into a valuable commodity.
