Using fossil fuels emits a lot of carbon dioxide. This enters the atmosphere and traps heat, warming the climate. Unless we curb our energy use, temperatures will rise beyond the 1.5 degree-maximum we’ve set ourselves. Retrofitting is a key tool in decarbonising human activity and therefore preserving the environment. But how exactly can we make energy use more efficient?
Before sustainability became a buzzword, buildings were constructed using traditional methods “without integrating energy preservation techniques”. This leaves us with a lot of work to do to make existing stock climate-friendly. Retrofitting is a very tangible step to achieving this goal.
Even a brief dip into literature around the future of conscientious energy use consistently brings up these three measures for improving efficiency:
- Greening the grid by increasing the presence of renewable sources.
- Reducing the need for energy.
- Making the energy we do need to use go further.
In this article, we’ll take each of these themes in turn and investigate how better energy efficiency can be achieved.
Greening the Grid
To stay ahead of 2050 climate change limits, we need to reduce carbon emissions by 6% per year. But in 2019 they were still increasing! What is seen as the solution may in fact be the problem: the shift from oil and coal to electricity for our everyday operational demands. Forbes reported that electrification of heat and charging ever-more electric vehicles will see “consumption increase two-fold by 2050”. What can we do to redress the balance?
Close-Down Coal and Obliterate Oil
It may seem counter-intuitive, but increasing electricity use “has a higher carbon content due to the high proportion of fossil fuels used in generation”.
So even if we’re retrofitting (and building new) to run on electricity, we’re not automatically eliminating the combustion of oil, coal, and natural gas from the energy pipeline.
To do so, we need to phase out old-fashioned power stations. It’s tricky, given that fossil fuel plants are among the cheapest to run. Or at least, this was the case until recently.
Invest in District Energy
According to the International Renewable Energy Agency, widespread up-scaling of solar generation led to hardware costs plummeting by 93% over the decade to 2020. In the same period, expenses for wind power installations declined by up to 56%. Improved technology is increasing yield, meaning we can power more and it costs less using:
- Concentrated solar panels – mirrors maximise how much sunlight is received and converted by the units.
- Higher turbines with larger and swept (shaped to reduce resistance) blades.
All in all, newly built renewable generators now significantly undercut any fiscal advantages of fossil power plants. This goes some way to explain why applications for new coal mines in the UK have been declined. By increasing the use of renewables across the globe, this shift will replicate in every region.
To achieve this, states should invest further in the technology and distribution of solar, wind, and hydropower. Administrations and energy companies need to collaborate to set up infrastructure that makes the energy they offer accessible across the grid.
Generate Your Own Power
We needn’t rely on the major players to act. Sure, individual homes, offices, and public buildings can shop around for tariffs that solely use renewables but when renovating, we can gain some independence by opting to add rooftop solar panels to generate our own power. That’s Retrofit 101.
What is less documented is that prosumers can make use of the up-and-coming option of home turbines. “In theory, a 10-kilowatt wind turbine should be able to offer the average family all the energy they need for yearly use.” In reality, this is only an option if you:
- Have a plot of land to install them on.
- Get permission to erect one – the higher it is, the less wind resistance the land creates, making them more efficient.
- Can afford to spend approximately $1,000 per kilowatt required for your household.
Hybrid systems – combining solar panels and wind turbines – optimise the home-grown energy farm with potential for round-the-clock generation and power on-demand. Multiple buildings can even pool their power into a microgrid to increase capacity and greater independence from the national grid.
Reducing Energy Consumption
Even though we’ve got a supply of clean, green energy, if our buildings leak heat and light, we’re still causing an ecological nuisance. There are plenty of ways around it.
Solar Water Heaters
Worldwide, 25% of domestic energy use is expended on heating water, and 12% in commercial buildings. Directly heating water by harnessing sun exposure can save up to 70% of this energy.
Read more about efficient water use here.
Net Zero Buildings
Net zero buildings (or ‘carbon zero homes’) are the ultimate in energy efficiency, producing as much power as they consume. Battery units allow the electricity to be stored for times of demand, too.
While current technology makes it hard to reach net zero targets, the Energy Performance of Buildings Directive encourages EU states to commit to nearly-net zero for all new buildings, including generating power “on-site or nearby”. Retrofitting with PV units or to Passivhaus standards means existing stock can achieve the same level of efficiency:
“Among energy retrofit measures, thermal improvement of [the] building envelope provides the most significant benefits in terms of both reduced final energy use and CO2 emissions.”
Piccardo, Dodoo, and Gustavsson
There is an element of compromise to be made. One tenant in a retrofitted passive house spoke of being unable to affix anything to the wall, such as picture hooks and blinds. It only takes a moment of absent-mindedness to bang a nail into the wall and breach the insulated seal.
Behaviour Change
AIA California, a platform for American architects, advises we all advocate for a change in “building codes to set minimum energy performance levels and minimum technical requirements” and that officials enforce compliance.
Establishing a policy that requires all builds to be nearly net zero by a specific date, or face penalties, would certainly force an upturn in investment and urgency, say Bankers for NetZero.[1] This should be well documented in advance, as the emphasis is on encouraging retrofits, not filling the coffers.
Energy conservation programmes can do a lot to raise awareness and alter habits. Thailand’s ENCON provides funding raised from levies on petrol producers for projects that:
- Develop energy efficient and renewable technology.
- Design outreach campaigns that elicit adoption of these resources.
You can read more about the programme here. While “energy conservation programs can be used to incentivize reduced energy consumption”, awareness alone is a massive influence in changing consumers’ habits. Often, knowing the problem and what to do about it is all that is required. For those that need more convincing, it at least lays the foundations for change.
Play Your Part, Think Smart
Smart thermostats provide opportunities to programme the temperature precisely as you need it, which can reduce the demand for energy by 10%. There is maybe a little irony that to achieve this, we need to power one more device. Using apps or timers, we can now control exactly when heaters switch on and off – even when away from home. What could be better than saving costs when you’re out and still switching the heater on in time to return to a cosy home in winter?
We love the WWF’s simple but effective advice for further reducing energy demand. Our top picks are:
- Use laptops instead of desktop computers – they require 5x less electricity.
- Turn off any devices when you’re not using them. Standby mode is a (vampire) power-drainer.
- Defrost the freezer regularly to help it stay efficient.
- Ditch the clothes dryer. Hang-drying uses no energy at all.
Making Energy Go Further
By now we’re saving energy, but there’s more we can do. How about trying the following and stretch the little power we’re using a little further? It’ll save you money, so surely, it’s worth giving it a go.
Treat Yourself to Something New
Energy-efficient lights, heat pumps, water heaters, showerheads, aircon units, and space heaters offer very direct solutions. Increasingly, they require less energy to perform to expected standards.
High-efficiency tech is easily available and increasingly affordable; it is fast becoming the only option when buying new. Incandescent lightbulbs, for example, are being phased out in favour of LED equivalents. A++ standard bulbs eliminate the 90% of wasted heat of old ones.
Check the Ratings
Japan’s Energy Saving Label Program is a 5-star sticker-based system for rating products. Energy Star in the USA actually provides a tool with personalised steps for choosing the right appliances, renovation, and habits to improve efficiency for your property.
Many regions now have an energy efficiency standard, either as a guide or enforceable objective. The South African Accreditation System (SANAS), for example, requires property owners to assess their properties and meet D-rating standards by 2023. The scale ranges from A (most efficient) to G.
The Chilean Law on Energy Efficiency (CLEE) is expected to be similar when fleshed out, issuing mandatory certificates to buildings that comply. Ireland’s Building Energy Rating (BER) is also an A-G system, while the Energy Performance Certificate (EPC) is active in parts of Britain. It’s worth noting that the exemption of some buildings like places of worship can be frustrating for those who feel we should be doing more to combat emissions.
All the usual retrofitting measures are the ‘gold standards’ for improving your building’s rating. Adding that insulation, triple glazing, and tankless water heater will help you rise through the ranks.
Choose Well, Invest Wisely
The Guardian spoke to a number of families using retrofitted residential heat pumps. Although reviews were mixed, they all lead to the same conclusion: these work if the right model is installed.
There are many lessons to be learnt from experience, specifically for heat pumps:
- Don’t rely on a heat pump without combining it with insulation and double or triple glazing.
- Underfloor heating boosts their effectiveness.
… and generally for retrofits:
- Assess the needs of the property before choosing what to implement.
- Avoid cutting corners, buying cheap, and bad, unprofessional advice.
- Choose a reputable brand, even if it’s more expensive. They are more reliable and perform better for longer.
- Technology is forever advancing. Don’t be put off because of past experiences.
Plug the Leaks
Cracks, ill-fitting doors, and broken window seals let draughts in and warm air leak out. Leave these untreated and you’re likely to be using more energy than necessary to compensate.
Luckily, there are many really simple solutions that can be incorporated into any shallow retrofit that make a world of difference.
Door-seal kits cover the gap between internal, external, and loft doors, windows, and their frames, preventing unwanted airflow between rooms and through the building envelope. They can either be screwed on or applied as self-adhesive strips for immediate effect. Brushes – or a ‘weatherbar’ – affixed along the bottoms of doors serves the same purpose. Similar devices cover keyholes.
Draught-proofing unused chimneys is another way to prevent heat from escaping. Simple terracotta caps or excluders will do just the job. To finish, piped caulking clogs those pesky cracks to keep you toasty.
Energy Efficiency in a Nutshell
Investment in retrofitting allows us to manage energy use and limit the impact our built environment has on the natural world. We shouldn’t implement measures in isolation. Combining energy-efficient renovations with renewable energy sources and limiting the amount of power we need to and do consume will have wide-reaching benefits. And although it might still need significant investment, as we’ve seen, retrofitting is not so hard to do. The time for excuses has ended. The time for action is now.
[1] Volans, Re:Pattern and APPG on Fair Banking. (2021). Bankers for Net Zero briefing: The Retrofit Revolution. https://volans.com/our-work/