If the UK’s going to reach net zero by 2050, it’ll have to make some big changes.
At Area, we believe it’s our responsibility to help get us there. After all, the built environment is responsible for around 40% of the total UK greenhouse gas emissions - and 80% of the buildings for 2050 have already been built.
With all this in mind, we must find ways to decarbonise existing stock as soon as possible. And it’s here where renewable energy steps in.
Renewable energy comes from natural resources that can be replenished quickly. These include things like sunlight, water, wind and waste. The good thing is that generating energy from these types of sources reduces our dependence on non-renewable sources like fossil fuels. These, in particular, are especially harmful as they take millions of years to replenish. On the flip side, renewable energies produce much less carbon dioxide and other greenhouse gases – a major cause of climate change.
The most widely used renewable energy sources include:
Solar energy - harnessing radiant light and heat from the sun to generate electricity, e,g. via solar panels.
Wind energy - generating electricity using wind power (usually via turbines).
Hydro energy - Hydropower (or water power) produces power via falling or fast-running water.
Biomass energy - this is where you use plant-based material as fuel to produce heat or electricity, e.g. waste from industries, households or farms.
What’s important to remember, though, is that the technologies using renewable energy are likely to have a carbon footprint of their own - albeit a relatively small one. But as they’re not reliant on fossil fuels, these low and zero-carbon technologies can still contribute to a much greener business.
As the name suggests, low and zero-carbon technologies (LZC) are types of tech that emit no to low levels of CO2 emissions. But as well as being better for the environment and putting you on course towards net zero carbon, renewable or LZC technologies can also generate a significant proportion of a building’s heat or electricity.
However, not all technologies will be suitable for every scenario. And when considering renewable energy and LZC tech, you’ll also need to stay mindful of things like technical feasibility, budget, project scope and ROI.
It’s also important to note that incorporating renewable energy and its associated technologies is far more effective within buildings that have an energy-efficient fabric. For example, in buildings where heat demand and loss have both been reduced to a minimum. One effective way to do this is through proper insulation. Take a look at the structural integrity of your building and check cavity walls, flooring and ceilings. It's also worth ensuring you have the right standard of double glazing in windows. They may seem like small changes but they can make big savings on energy consumption and, crucially, those ever-increasing bills.
So what types of LZC technologies could your business implement?
Renewable heat technologies can provide heat for hot water, space heating or both. In fact, any form of heat energy extracted from a renewable (or low carbon) source can substitute the heat produced by a system that’s powered by fossil fuels. Widely adopted heat-generating technologies to consider include:
These systems use rooftop collectors to absorb solar radiation, before converting it into heat throughout the day.
So what sort of heat generation can you expect?
Well, the average building with a south-facing roof could produce around a third of the hot water needed for an office throughout the year. However, it should be installed alongside an auxiliary water heating system, e.g. a point-of-use electric water heater, in order to make maximum savings. Just bear in mind that this system must be sized for the building's specific hot water requirements. But on the plus side, it requires minimal maintenance and there are little-to-no ongoing costs once it's fitted.
These systems turn heat from the earth or various water sources, e.g. rivers, lakes and streams, into a space heating for buildings. Simply put, these heat exchange systems work a lot like a reverse refrigerator. The two systems work on the basis that both ground and water will provide a relatively constant temperature - regardless of outside weather conditions.
So how effective are these types of heat pumps?
Well, this depends on how you use them. When heating and cooling a building on the same day, the systems are much more efficient. In fact, this system’s particularly effective in offices where chilled beams are used to distribute the cool air. Undoubtedly, though, these types of heat pumps are a much more sustainable alternative to air conditioning systems. They’re also unobtrusive, easy to maintain and relatively flexible when it comes to installation.
These pumps absorb outside heat, before using it to warm a building’s interior. There are two types of air source pumps:
Air-to-air systems - where warm air is circulated to heat the building via fans. These are most suitable for buildings where little to no hot water is required, e.g. retail outlets.
Air-to-water systems - these transfer heat from the outside air to water, warming rooms via radiators or underfloor heating. It can also heat water stored in a hot water cylinder for hot taps, showers and baths - so much more suitable for later office blocks.
It’s worth noting that both types of pumps produce hot water that’s at a lower temperature (typically 35-45C) than standard boiler systems. With that in mind, they will work more efficiently with underfloor heating (where the temperature differential is lower). They can still be used with radiators but these must be dimensioned (sized larger than the ones required by conventional heating systems) to run at the lower temperature. That means you’re also going to need some additional space - and some specialist maintenance. The capital costs are still relatively low, though, and they certainly use fuel efficiently.
District Heating (or community heating schemes) provide heat from one central source to multiple buildings. Schemes can dramatically range in size; from one tower block with a central heat source to citywide schemes, connecting multiple public and commercial buildings. These types of heat sources can include:
Conventional boilers - these either use conventional fuel, e.g. gas or oil, or renewable fuels such as biomass, domestic or agricultural waste.
Combined heat and power (CHP) plants - here, the heat from electricity production is captured and used to generate more electricity. Alternatively, it can be distributed elsewhere via a heat network.
Using waste heat - this is produced from industrial processes, e.g. distilleries, and then used to heat other locations.
Generating electricity from renewable sources dramatically reduces the amount of conventionally generated electricity that needs to be bought. This is so important when you consider for every 1kWh of electricity used from conventional methods of generation, over half a kilogramme of CO2 is released into the atmosphere.
The most effective renewable electricity sources are:
There’s no doubt about it, solar power is one of the world’s fastest-growing renewable energy technologies. Particularly solar photovoltaics which are expected to produce around 22% of global electricity by 2050. To put that figure into context, that’s the equivalent of more than 3 Gigatonnes of CO2.
So how does it work?
Well, photovoltaic systems require daylight (not direct sunlight) to generate electricity. And they’re most suitable for buildings with a roof or wall that faces within 90 degrees of the south; this is just as long as no other buildings or large trees overshadow it. It's also worth noting that if the roof surface is in shadow for parts of the day, the system’s output will decrease. Finally, photovoltaic panels are not light. So it’s crucial that your roof is strong enough to take their weight.
As well as having no moving parts and being silent in their operation, solar arrays are also incredibly versatile. You’ll find they come in a variety of shapes and colours; everything from grey solar tiles that mimic traditional roofing to transparent glass cells you could use on conservatories. And because photovoltaics are so adaptable, they’re widely used in conservation areas and on listed buildings as well.
This is a popular choice for the British public, with 77% supporting onshore and 81% favouring offshore wind energy.
For good reason too.
Wind Energy is proven to be a well-developed source of renewable energy. That's because the UK and mainland Europe both benefit from a favourable and often windy climate. Consequently, this has led to wind energy having a total net installed capacity of 189 GW. In fact, it’s the second largest form of power generation capacity in Europe.
So how does it work?
Wind energy can be used to generate electricity via turbines. These are usually positioned on wind farm sites and convert the kinetic energy of air currents into electricity. Land for wind turbines consists of large, multi-megawatt wind turbines and can be located both onshore and offshore, feeding their electricity directly back to the grid. However, small-scale (1kW – 15kW) wind turbines can also be pole or roof-mounted. It’s worth noting, though, that a wind survey will be required to verify the viability of this.
But when it comes to renewable energy, there are also solutions that can provide heat and power.
Combined Heat and Power (CHP), or cogeneration, is the simultaneous production of electrical and heat energy from a single source. This source can be from renewable, low or zero-carbon energy, e.g. solar energy or biomass. The systems themselves can also be employed over a wide variety of sizes, applications, fuels and technologies.
But how does it work?
Well, in its simplest form, CHP uses a turbine to drive an alternator. And the resulting electricity from this can then be used either wholly or partially on-site. What’s more, the heat produced during power generation is also recovered. Usually, this is in a heat recovery boiler which can be used to raise steam for a number of industrial processes. This could be to provide hot water for space heating or, with appropriate equipment installed, cooling as well.
It’s because cogeneration systems make such extensive use of the heat produced during the electricity-generation process - not to mention the fact that they are typically installed on site - that they can achieve huge overall efficiencies; these are often in excess of 70% at the point of use.
In fact, cogeneration can be used to provide energy for a single home, large industrial plant or even a whole city. That makes this type of system particularly useful for buildings that either need a lot of energy or operate around the clock, e.g. leisure centres, hotels or hospitals.
Undoubtedly, cogeneration can enable massive CO2 savings. But just be mindful that maintenance of this system can be intensive and sufficient base thermal and electrical demand will also be required.
Looking to integrate renewable energy into your business? In our experience, it’s a good idea to engage like-minded partners early in the process.
Duncan Morris, our Head of Sustainability says: “At Area, we love to work with clients and contractors that are as passionate about reducing carbon emissions as we are. It’s not just an add-on as part of our corporate responsibility to the planet, it’s fundamental to our business.”
But what about carbon offsetting?
“Sure, a focussed approach to using verified carbon offsetting schemes has its place, particularly in the early to mid-stages of the journey towards carbon neutrality - but it's no silver bullet,” says Morris. “Instead, we focus on decarbonising our business and supply chain to stop carbon from being released in the first place. Then, we can target any remaining emissions via offsetting schemes.”
But this is a global issue and organisations must be united in their approach to carbon reduction to achieve meaningful change, warns Duncan.
“For the built environment to achieve zero carbon, we need buy-in from multiple stakeholders at design, construction and operational stages - tricky, we know. At Area, we're fortunate that we can influence all levels, from sustainably considered design and construction processes right through to training the end user. The latter’s a fundamental element of our soft landings approach before handover. It ensures our spaces are always designed and built with sustainability at their core. Importantly, it allows participants to make the best use of these spaces, whilst still minimising their environmental impact.”