My father always believed in tidal and wave power, the tide is a constant and the most reliable power on the planet, he would tell me and the power that is stored in waves, unimaginable. That was some 50 years ago when he was talking about electricity from the sea, today it has become a reality.
In the late 1950s nuclear power was to be our source of power, it would be so cheap, they told us that it would cost more to send out the bill than the cost of electricity. Whoever suggested that had not calculated the cost of decommissioning and how we would store the waste from such plants. Even after all the test bores in rocks around the country and talk about encasing the waste in glass and storing it deep under the Cumbrian hills, we still do not have a solution.
With coal still cheap there was no real hast for a solution to powering the UK now however the reality of global warming has kicked in, we need a clean soars of power.
First to appear were onshore wind turbines, there was a big hue and cry about them at first, they were noisy, killed birds and unsightly, but they made commercial sense, so they kept coming.
Then came offshore wind turbines and now floating offshore wind turbines.
Tidal are now catching up with offshore wind turbines, mainly because the tide is so predictable. One line of tidal power turbines stretching across the Pentland Firth they say will produce enough electricity to power the whole of Scotland’s needs.
This brings us to the second problem with all of the above systems, we do not need the same amount of power all of the time, and what do we do when the wind does not blow?
back in 1959 work was started on the Cruachan Power Station, a pump-storage hydroelectric power station in Argyll and Bute. The scheme can provide 440 MW if of power and has a capacity of 7.1 GWh. The turbine hall is located inside Ben Cruachan, and the scheme takes water between Cruachan Reservoir to Loch Awe, a height difference of 396 meters (1,299 ft).
The system is simplicity itself, water flows from the dam to the pumping station during peak times, then the turbines can be reversed to send water back up to the reservoir when the electricity is not needed. I can also, take surpass off-peak power from the grid to pump water to the high reservoir.
Batteries have been around for more than one hundred years, but only in recent years has batteries developed where they are small enough and efficient enough to be used to store electricity for the grid. Scotland has a 20 MW energy storage facility at Broxburn in West Lothian. Its response time in delivering to the grid at peak demand is said to be the fastest of its kind, being able to respond to the grid in milliseconds when required.
Alternatives storage systems
For years now there has been a wind power generator down at Leaven Mouth. I had passed it many time and had not given it a second thought, then one day I was cycling down by the dock and I read the notice on the building, adjacent to the wind-powered turbine. It was not simply producing electric power but experimenting in using that power to produce hydrogen, like gas it could be used as a fuel to drive transport or used for cooking and heating as a clean alternative fuel for natural gas.
We already have hydrogen buses in Dundee so hydrogen is truly an alternative to petrol and diesel. Hydrogen would replace natural gas too as a green alternative for heating and cooking. The Company at Leven Mouth hopes to have it operational, and commercial viable within three years.
Offshore wind would be used to generate the electricity required to create the hydrogen from water through a process called electrolysis.
New pipes will be laid alongside 1,000 properties, meaning homeowners would have the choice of receiving their existing gas supply or hydrogen alternative. Sadly we have to wait for private companies to come up with the money to get such innovations off the ground, and still it has to run alongside and not replace natural gas, because it is all commercial and outwith the control of the Scottish government.
Back to storing electricity
I read with interest that a company at Leith (Edinburgh) are developing a Gravity Storage System,
The company, Gravitricity, has set up a £1 million demonstration at the Forth Port’s Prince Albert Dock. It aims to use underground shafts and massive weights to store large amounts of energy.
The 250KW demonstrator comprises of a 15-metre high tower, two 25-tones weights, suspended by steel cables and two fully interconnected generators units, they hope the system will be fully functioning by April 2021.
This is not the first time this has been tried, but as far as I know, tried in Scotland and it is the speed of change that has impressed me.
The first gravity storage system I heard of was way back in 2019, seems like an age ago now. It was developed by Energy Vault the system had six-arm sitting on top of a storage tower, that raised and lowered concrete blocks and storing the energy in a similar method to pumped hydropower stations.
Comparing different systems and their efficiency will always be a challenge when they are still at the development stage. How many of these ideas will ever leave the development stage is debatable, more so with the more ambitious systems. For national governments are unlikely to invest in such large projects past the development stage and companies are more interested in a quick return on their investments. So sadly it will not always be the best we see come to fruition but, the ones that show potential for profit in the short term. Begging the question, “Who does run our country?