Energy consumption is a major source of carbon emissions and environmental damage. Home heating and energy generation result in over 55% of greenhouse gas emissions. However, we also can’t be expected to afford off-grid living or live as complete hermits, so here are some handy tips for which fuels can be the best to minimise the damage for 3 popular technologies: commercial boilers, biomass heating, and heat pumps.
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Think Before Going Electric
Electric boilers are increasingly in the conversation these days as countries are looking to cut their ties with the gas grid. The UK is looking to phase out gas boilers and other countries are following suit. Similarly, even the US and Australia are pumping funding into renewable sources of energy and heating.
Electric boilers have many benefits: they’re compact, they are easy to install, they can work without a gas main, and they carry zero chance of gas leaks. But there is an issue with the argument that they will be automatically more sustainable.
While it is true that electric boilers don’t use fossil fuels directly, they are dependent on the energy grid which is run on non-renewable sources. Moreover, despite the fact that they have higher efficiencies than gas boilers (99% versus 94% max), electric boilers can use up more energy overall.
They are marginally better for the environment but their operating costs can be an issue. Electricity is more expensive than gas which could spike your energy bills. In many regions, it is easier to get LPG or oil delivered than to rely on an electric boiler.
While policies like the gas boiler phase-out are well-meaning, there are still issues with electric boilers. Ultimately, the best boiler for a 3 bedroom house in the UK and the US is still a gas boiler. Unless you can afford a biomass setup or attach your home to solar panels, you will be reliant on fossil-fuel-based heating in one way or another.
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How to do Biomass Right
Biomass is probably the best kind of boiler you can obtain since it uses a renewable source that is often less volatile (although prices have increased considerably in recent years due to global instability). Biomass can still be fairly cheap overall but when is it most sustainable?
Biomass fuels, derived from organic materials, are categorized mainly into woody fuels, animal wastes, and municipal solid waste (MSW). Transportation of these fuels can be unsustainable sadly, even though they are good for the environment. That’s why you should source them locally.
The evaluation of biomass fuels should also take into account the supply stability, total available quantities, competitive markets, and costs associated with their collection, processing, and (as mentioned above) transportation.
Wood Pellets derived from compressed industrial waste wood or forestry residues are a highly efficient source and comparatively easily renewable. They have low moisture content and burn better than raw wood. The sustainability of wood pellets largely depends on responsible sourcing and the use of waste materials from sustainably managed forests. That’s why it’s better to use pellets from softwood forests since they are quicker to regrow.
Residues from agricultural production, such as straw, husks, and shells, can be sustainable as well. Making use of waste is always better than chopping trees, however, sustainability depends on a few factors. The crop needs to be made with agricultural practices that are sustainable and quick to grow to serve as a fuel. The cultivation should be in line with food production and have minimal effects on biodiversity.
Similarly, utilizing residues from forestry operations, such as branches, stumps, and sawdust, can be sustainable. This also helps reduce waste and should be sourced from sustainably managed forests. Look for sources that would not harm the soil during the extraction process.
Then there are the crops that are grown for energy production, such as miscanthus, switchgrass, or short-rotation coppice. Aside from being sustainable (when properly grown) they offer benefits like carbon sequestration, soil improvement, and biodiversity support. However, their sustainability is not a guarantee. They can displace food crops when mismanaged or lead to deforestation.
All of these can serve as proper sources of renewable heating but it takes a bit of research.
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Optimising Your Heat Pump Efficiency
Heat pumps are often touted as the most efficient source of heating and cooling you can have. The technology is great, but there are situations where you may not be getting the most out of it. This is especially pertinent since they can be quite the investment.
Heat pumps are far better when they are paired with good insulation. Without it, you might be losing a lot of that heat or cold that is generated, costing you and the environment more in the long run.
Air source heat pumps are the cheapest option but they can be the least sustainable and have the highest relative operating costs. They are still a handy tool that can work great for most homes in an area where the climate does not swing too wildly in either direction but still requires some heating and cooling.
Water source heat pumps can vary wildly based on installation and seasonality. This is both a good and bad thing since at their best they can have a 600% efficiency over standard boilers. However, the fact that water is a good conductor of heat also means that its properties fluctuate a lot, leading to unstable efficiency readings. Water source heat pumps are thus the most sustainable in stable climates without intense variation, otherwise you might risk having inconsistent electricity bills.
In terms of stable efficiency, ground source heat pumps are the best. The soil under the earth is always at the same temperature. They may have a lower height in efficiency than water source heat pumps but they are good to go all year round. Additionally, bodies of water near homes are rarer than having free land, so installation may be more feasible even if it is more expensive.
