Sunday, June 23, 2024

How to Transition to Net Zero: An Engineer’s Perspective

It’s no secret that time is running out on our journey to net zero. Taking the path of decarbonisation is challenge enough for small enterprises but this escalates to a daunting scale when it comes to large energy users across multiple buildings and sites, including business use estates and education, particularly university campuses. It’s all well and good encouraging the people going about their business on the estate to use less energy, but compliance can’t be forced and even with perfect adherence it’s only going to get you so far.  It can seem a daunting challenge, even for seasoned Estates Directors. Nick Boid, Technical Director, Energy at Buro Happold, provides insight into how large estates can get the ball rolling and what to expect along the way, there is a lot of ground to cover before you can start to plan to decarbonise.

Where to Start?

The key to any solution always lies within your understanding of the problem, making the transition to net zero is no exception. You need to first understand where you are currently, to see how far away you are from where you want to be. This means the first step for any estate is to establish the baseline, in other words, do you have good metering data? If the answer is no, then the first step will be to get that data. This could mean installing temporary metering equipment, something Buro Happold have done for a number of clients to get a sense of what they are using, when and where. After all, if you can’t measure it, you can’t manage it!

If you do have comprehensive metering data and with it a full picture of your estate’s energy usage, your first step will be to analyse and importantly, understand that data. Consider where the estate is performing well and where changes need to be made. Look at ways to reduce your energy consumption before you take any further steps because this will only aid the rest of the journey.

A big benefit of being in control of your energy data is that you can use it to inform decision making, particularly when it comes to funding. In order to facilitate future changes to decarbonise it will be critical to funders, whether internal within the organisation, or external, to truly understand the benefit that will be created against the investment. Having visibility of what energy is being used every month, how it is being generated, how much is being spent, and what the carbon emissions are will be invaluable when it comes to getting finance.

Capacity that is fit for purpose

And timing is everything (apart from data). From an engineer’s perspective, it’s especially useful to know when energy is being used, when in the day and when in the year. Energy used for heating, for example, is going to be disproportionately used in the winter. Analysing how much energy an estate uses during peak times will drive the capacity of the equipment you need and will typically determine your capital cost. The trap a lot of estate owners fall into is assuming that the equipment they currently have in place is the right capacity, so replace it like for like. However, in many cases estates have an unnecessary capacity surplus because it hasn’t been installed based on actual use. This reaffirms the importance of having in depth metering data, in an ideal world this would be half-hourly usage data, because you can potentially make a substantial saving on the new solution by not oversizing the new equipment.

Build a demand model

The next stage for Estates Directors in the transition to net zero is building a demand model based on the energy use data. You can then compare the model to industry benchmarks for energy use, making it clear which buildings are performing well and allowing you to identify any potential outliers. This approach of cross referencing also enables you to validate the data, if it looks wildly different from the industry benchmarks then the chances are, there is something wrong with your measuring equipment. Inevitably some assumptions will need to be made when creating a model, but you can build in the life cycle of the estate, including known capital plans, for example, are there plans to demolish some buildings or sell any?

An additional benefit of building a model is that it highlights the high energy users on the estate, for example, if there is a data centre on the estate this will likely use the most energy. Once you understand the uses of energy across the estate, you can then look at the applicable options for energy efficiency such as replacing lighting with LEDs or implementing scheduling controls. You should also be able to see what, if any, building improvements need to be made and where, do you need to improve the glazing in some buildings but the cladding in others, for example.

A good model will then reveal the savings you will make from improving the energy efficiency of the estate. On average, you can expect around a 10-30% saving but this will vary from estate to estate depending on factors such as age and condition.

Switch to cleaner, greener energy supply

Once the model is complete you can turn your attention to more sustainable energy sources. This will be unique for each estate, dictated by the estate’s characteristics. For example, is there a data centre on site? You could utilise the waste heat this kicks out to heat other buildings. Have you got any groundwater, or water sources that could be used as low-grade heat sources combined with heat pump technology? Would a wind turbine be appropriate or solar PV panels for renewable electricity generation? It’s also worth considering if you can store energy. having the capability to store low carbon energy for example, through battery storage, can offer flexibility in how you use the energy produced on your estate and help prevent waste.

The answer could be a combination of clean energy solutions. Are there any steps you need to take before changing your energy supply? If you’re operating an existing heat network using steam, the most sensible first step is to try and lower your operating temperature. This will make your energy solution more efficient in the short term and prepare the network for lower temperature heat generation technologies such as heat pumps in the future.

Something you might find surprising is that it’s much harder to upgrade/retrofit buildings than it is to switch energy sources. The general consensus seems to be that we have to upgrade all our buildings until they are all at a certain standard, and then we make the heat generation switch to say, heat pumps. However, this fails to consider that the cost per tonne of carbon saving gets higher the more retrofitting you try to do. Usually, there is also a limit as to how much disruption you can cause. For example, will work have to stop while you are retrofitting a particular building or is there somewhere you can temporarily move the operations? One solution is to prioritise making small, less invasive changes to the building fabric ahead of changing the energy source, for example removing drafts and reglazing windows. This would decrease the level of disruption while increasing the efficiency of the new energy source, and of course, reduce the associated running costs.

When it comes to cutting out carbon – make a plan

You know what they say, fail to plan, plan to fail. Once you have your metering data, model and have thought about plausible clean energy sources it’s time to sit down and synthesise this into a decarbonisation plan. This needs to cover the broad strategy, proposed timeline and an estimated budget that includes both the cost of the net zero transition and the impact on operating cost. You can’t do everything all at once, so think about the most sensible path to get to where you need to be. For example, if you have a heating system with five boilers, it may not be financially viable to replace them all at once. But you could replace one now and the rest over a period of say, 10 years, which would both spread the cost and give you time to get comfortable with the new technology.  

In your plan it’s particularly important to consider how you’re going to fund the transition to net zero. Can senior management solely fund the project? Will you need to find a private investor or apply for public funding? There are many private organisations looking to put money into the improved energy performance of large estates, so this is worth considering. It is quite clear that in this current economic environment that the pot of public money for decarbonising public estates will be limited. Which means that, even to partially fund the transition to net zero, you need to have a comprehensive plan ready to submit quickly because the competition will be fierce. 

Once you’ve started implementing changes, it’s important to go back and keep your plan updated on how things are going. Keep a close eye on factors like energy price changes and review your plan every couple of years.

What is the biggest challenge?

The biggest challenge faced by most estates when it comes to transitioning to net zero is getting off the gas grid.

Large estates often already have an onsite heat generation solution such as gas CHP. Historically this has worked well because gas is cheap, so it has avoided estates having to fulfil their heat demand requirements through expensive electricity. However, with the main priority now being to achieve net zero, this doesn’t make sense from a carbon point of view. Electricity is becoming cleaner, and crucially, we need to stop burning gas.

Transitioning to electrification of heat and the effect this has on the campus electrical demand and infrastructure is a major challenge facing many estates and one that needs to be solved in a pragmatic way. One way to approach this is to confirm what headroom is currently available on your incoming supply and focus on what buildings can be implemented into that first phase heat transition. Then you can consider increased grid connection and infrastructure reinforcement as a longer-term plan.

Inevitably the transition to net zero for any estate is going to be a lengthy, multifaced process. All estates will use roughly the same decarbonisation route map, but of course, the specifics will vary widely.

The main pieces of advice to get you moving in the right direction are to get good metering data, make a plan and start by getting started. Even taking small steps towards decarbonisation will be better than doing nothing at all.

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