Green, ethical, energy issues in the news

Martyn1981

Renewables investment in UK will fall 95% over next three years – study

Doesn't make for pleasant reading. Having invested in expensive and medium cost on-shore wind and PV, the government seems determined to avoid investing in cheap on-shore wind and PV. Go figure!

The good news is that globally things are going much better.

tunnel

Here's a nice bit of news concerning China and RE. Shame we don't follow suit!
http://uk.reuters.com/article/china-energy-renewables-idUKL4N1EV1GX

Martyn1981

If anyone's interested in the rapid development of technology, then this short article may be of interest:

Vattenfall unveils 340MW Thanet 2

Thanet 1 used 3MW turbines in 2010, and currently 7-8MW monsters are being deployed in some places. But this article suggests that giants of up to 10MW might be built.

Martyn1981

Some interesting numbers on electricity generation in 2016, and lots of 'firsts' as our generation mix is changing:-

The UK generated more electricity from wind than from coal in the full calendar year of 2016

The milestone is a first for the UK and reflects a collapse in coal generation, which contributed just 9.2% of UK electricity last year, with 11.5% from wind. The coal decline saw its output fall to the lowest level since 1935.

It also means CO2 emissions from UK power generation will have fallen by around 20% in 2016, as coal was largely replaced by lower-emissions gas. This reduction will be enough to cut overall UK CO2 emissions by 6% for the year, if other sectors’ emissions are unchanged.

Martyn1981

Potentially good news for tidal generation:

Government review likely to back Swansea Bay tidal lagoon

He added: “Swansea is a prototype for a series of much bigger lagoons across the UK. Because bigger lagoons are able to pass far greater volumes of water through their turbines they are guaranteed to generate far cheaper power.”

The company believes that if the six projects were completed at scale, they could together provide 12% of the UK’s electricity for about the same subsidy as onshore wind or solar power today.

michaels

With an 'array' of tidal stations can you stagger generation times (at the cost of lower overall output) in order to smooth production towards times of maximum need (and output value)?

Martyn1981

michaels wrote: »

With an 'array' of tidal stations can you stagger generation times (at the cost of lower overall output) in order to smooth production towards times of maximum need (and output value)?

Yes. But you'll lose some efficiency. Ideally the lagoons are 'closed' till high tide, then the turbines start, and you have the greatest head of water (max outside, min inside). The opposite happens for discharge, you wait for low tide, then release the water.

In reality, it's a wider period, as the water can't just zip through. Giving 4 generation periods. I think total generation is about 14hrs, suggesting they generate for 3.5hrs on each in and out, with a 2.5hr pause between generation.

Generation will also vary, as obviously it'll be higher at the start*, then drop off as the water levels meet, and the head disappears. With hydro generation the amount you get is directly linked to the height the water drops - so for the same flow of water you'd get 10x the energy from a 10m head as you'd get from 1m.

But if peak demand is close, then you might let the water in (or out) a bit early. The generation will be lower, as the head will be less, but the need, importance, and of course value, of the leccy will be greater. Whenever tidal helps with the peak, it'll reduce the price of peak leccy.

Tidal does vary from spring tides (biggest) to neap tides (lowest), these happen twice a month. But the time and scale of the tides can be calculated centuries in advance.

*Perhaps generation isn't highest at the start. Given that generation last 3.5hrs, I wonder if water flows through from the start, but not fast enough so the head builds, then falls off as they start to balance again. This would give a bell curve generation period .... perhaps?


But, here's the fun part, not all of the UK has the same tide times, as it'll vary depending on location. Also, as we're an island, as the tide rises on one side, it might be going down on the otherside, so the more arrays, the better. However, nowhere comes close to the tidal range and sheer volume of water going up and down the Bristol Channel. [Edit: Oops! The Bristol Channel has massive potential for stored tidal, however there are many places in the UK which have tidal flow potential, where you place a turbine in the water where the flow rate is very fast, perhaps a narrowing or similar, and no water is actually stored. M.]

silverwhistle

Martyn1981 wrote: »

But, here's the fun part, not all of the UK has the same tide times, as it'll vary depending on location.

Come on Martyn, we're a nation of sailors! I've even got a tide app on my smart phone, and we know all about the double stand at Southampton etc. etc.. :-)

Martyn1981

Tidal lagoon: £1.3bn Swansea Bay project to be backed


Hopefully we'll get more news later, especially on the price. This article says:

TLP forecasts that its lagoons would generate power for 120 years and is seeking a 90-year contract at £89.90 per mega watt hour (MWh).

That would be below the £92.50 per MWh agreed for the new Hinkley C nuclear

However, in fairness to HPC its CfD is for 35yrs, though it's expected to last half the time at 60yrs.

I seem to recall a year or so back, that the lower 90yr CfD for Swansea might not have an inflationary uplift, which would actually make it quite cheap, but I could be talking rubbish. We'll see!

Martyn1981

SIR. YES SIR!

Ameresco to build renewable-powered microgrid for US Marine Corps

Ameresco will build a renewable-powered microgrid at a Marine Corp facility in Parris Island, South Carolina.

The project at the Marine Corps Recruit Depot (MCRD) includes 6.7MW of PV generation, a 3.5MW combined heat and power facility and a 8MWh battery storage system.