BY STEPHANIE CLARK
Renewables like wind, solar, hydro and biomass now supply the equivalent of 57% of the electricity used in Scotland.
And we’re getting better and better at using new technology to turn our weather into energy for our homes and businesses.
The hydro industry is one with a long history in Scotland, but it’s also one which has embraced technological innovation in recent years.
By definition, hydro-electric power needs a combination of rainfall and vertical drop, making the glens of Scotland particularly conducive.
While such locations lend themselves to hydro in terms of topography and precipitation, they commonly present challenges from a construction and operational perspective.
Hundreds of new schemes have been constructed and commissioned since 2010, many of which are a long way off the beaten track.
Operating such schemes successfully requires a combination of remote management and on-the-ground intervention.
Hydro schemes are built to last, and generate electricity on a steady basis for decades. As a rule, the underlying capital components – intakes, pipeline, turbine and generator – keep working with a relatively small amount of servicing and repair.
And that’s where the technology comes in.
Satellite broadband connects sensors at dams and turbines to the internet, letting operators see what’s happening in real time and, crucially, allowing any faults to be spotted as soon as they happen.
This high-tech comms kit means that for companies like Renfrewshire-based MEG Renewables, keeping in touch with their turbines is an office job rather than a Land Rover and wellies operation.
Business Development Manager Kenny Hunter said: “Some faults can be resolved remotely, but others require a visit, in the first place by one of the local caretakers, often an estate keeper.
“The real benefit of the remote connection is the immediate notification of a problem and the opportunity to respond quickly. Running at full power, a 500 kW hydro scheme can generate income of up to £2,500 per day, so time really is money.”
Farr Hydro is a 500 kW run of river scheme 10 miles south of Inverness, and is owned and operated by MEG Renewables and landowner Philip Mackenzie. In an average year, Farr Hydro will generate enough electricity to power the equivalent of around 350 homes.
The scheme has a satellite broadband connection, which allows MEG Renewables to monitor the performance of the scheme, and others which they monitor for third-party clients, from their base in the offices of parent company M & Co – the high street fashion chain – near Glasgow Airport.
The control panel, which is essentially the heartbeat of any hydro scheme, has been configured to issue email alerts when there are any issues with the scheme. In the case of Farr, that control panel has been manufactured and configured by North Lanarkshire business Kestral Controls.
The control panel sits in the power house at Farr, alongside the turbine and generator. Through a communication cable stretching nearly two kilometres to the scheme’s water intake, the control panel receives real-time data on water levels, and is programmed with algorithms which dictate how wide the spear valves on the turbine should open, and therefore how much power is generated.
Being a run-of-river scheme, there are no decisions as to when to generate at Farr. If the water is sufficient, the scheme will operate.
Those schemes which have a storage element – where a dam collects rainwater for later use – add another layer into their control systems, to factor in changing wholesale prices for electricity. In such circumstances, having remote access to the control panel is vital to optimising revenues.
While optimising the amount of electricity generated by hydro schemes, wind turbines and solar farms is a growing business, there’s one sector which has been neglected in Scotland to date: heat.
Keeping warm is responsible for 55% of the energy we use in Scotland, as well as the lion’s share of our carbon emissions.
Biomass boilers and anaerobic digestion are becoming more common in rural businesses, but harvesting the heat below our feet is another way to harness the energy we don’t even realise we’re wasting.
With the 11 billion litres of waste water created in the UK every day collected by 390,000 miles of sewers, our drains are a constant, inexhaustible energy source.
At Borders College in Galashiels, SHARC Energy Systems are using heat pumps to remove heat from sewage, then piping it around radiators to provide warmth for students and staff.
COO Russ Burton said: “The process is simple. Sewage heat recovery systems use a building’s waste water, which consists of what gets flushed away and is mixed with millions of gallons of hot water from showers, dishwashers and washing machines.
“That water maintains a fairly constant temperature as it travels through sewers to the treatment plant.
“Our system uses a filtration system to separate the solid and wet content of the sewage flow to allow extraction of sufficient energy to heat most buildings.”
The SHARC system at Borders College uses remote monitoring technology to keep operators in touch with equipment, meaning any faults can be fixed before they become an issue.
With huge changes made last year to the way renewable energy developers are paid for the energy they produce, and a growing need to reduce the amount of carbon emitted by our power sector, technology like this has a role to play.
And with new solutions for optimising the amount of energy produced by renewable technology appearing all the time, the future for green energy in Scotland remains bright.
Stephanie Clark is Policy Manager at Scottish Renewables