Green, ethical, energy issues in the news

Ben84

The UK government are apparently now aiming to shut down the remaining coal power plants in the UK by 2025:

https://www.theguardian.com/business/2018/jan/05/uk-coal-fired-power-plants-close-2025

A lot is said about the high CO2 emissions of coal power plants, but actually another big thing I'll be happy to see stop is the polluting ashes produced by coal burning.

EricMears

zeupater wrote: »

.. our trees must be much better quality than theirs though as they'll be costing £10each (£500million/50million trees)!


... wait a minute, how do trees possibly cost that much - you can usually get 3 for a tenner at Aldi in spring, guess someone's in for a windfall then (& that's cash, not apples!) ..

Does the £10 each perhaps include a contribution towards paying someone to plant them and someone else to supervise their first few years ?

zeupater

EricMears wrote: »

Does the £10 each perhaps include a contribution towards paying someone to plant them and someone else to supervise their first few years ?

Hi

That was my initial thought ... ... but, if it's anything like the 'carbon offset' scheme down the road from us, it'll be a case of plant & forget with a view to thin-out the surviving weaklings in about a decade or so ...

The same effectively happens at the local forestry commission site a few miles away, the estate managed woodland we get our logs from and the local NT site ...

If you think it through to some form of conclusion ....

Advertise for people to participate in a scheme like this to help save the planet & as long as the grub's decent & there's the promise of accommodation with a bar, they'd be inundated with volunteers ... it seems that professional teams average well over 2 seedlings per person/minute (1000/day), so even if a team was paid average wage and planted 100/person/day the direct labour cost would be around £1 each ... just checking on-line & bulk 4' oak trees are around £250/1000 inc VAT & delivery, so 25p each (£13million/50million trees) ... this means that there's still one very large discrepancy (likely £8.50-£9.75) for the sums to add to £10/tree ...

The national forest guidelines tend to suggest an initial planting density of 1600 trees/hectare, so 50 million trees equates to about 31000hectares, suggesting a land purchase (if there is any!) budget averaging ~£15k/hectare for what is mainly poor quality upland grazing, likely valued at approx 1/4 to 1/3 of that .... so even if all of the land needed to be purchased and none of the landowners saw the project as being an 'improvement' exercise, then there's still £hundreds-of-millions of discrepancy!! ...

I simply see it as someone, somewhere looking to make a management/administration/land-sale fortune out of the gullibility of those who would donate money to this project! ... unreasonable cynic, or one who applies basic project costing logic? ... unless/until there are more details we just can't tell! ...

HTH
Z

Martyn1981

Energy networks prepare to blend hydrogen into the gas grid for the first time

Energy networks are preparing to dilute Britain’s natural gas grid with low-carbon hydrogen for the first time in a radical bid to cut emissions from the country’s heating system.

Within weeks, a consortium of grid operators and experts will begin safety work in 130 homes and businesses before blending hydrogen into the methane-rich gas which has been used to heat British households and companies for over 50 years.

For over a year National Grid’s gas network spin-off Cadent Gas and Northern Gas Networks have studied plans to pipe hydrogen directly into the natural gas grid in partnership with Keele University. The Hydeploy consortium plans to inject enough hydrogen to fill 20pc of the gas grid, before rolling out the project across larger !areas.

I thought hydrogen was already being blended in upto 5%?

Crucially, KPMG said !hydrogen heating would be the least hassle for energy customers because very few appliances would need to be replaced.

The existing gas grid would need only minor upgrades because it was originally designed for hydrogen before the North Sea boom provided a flood of cheap natural gas to burn !instead.

Is that a reference back to town gas?

NigeWick

Martyn1981 wrote: »

A nice alternative/compromise is bio-gas

That's what Ecotricity is starting with their gas from grass plants. They reckon that grass from marginal land could supply 80-90% of our gas requirement. Now if all new builds were really well insulated......

lstar337

zeupater wrote: »

They're obviously copying us with our 'Northern Forest' announcement ... http://www.bbc.co.uk/news/uk-42591494 .. our trees must be much better quality than theirs though as they'll be costing £10each (£500million/50million trees)!:eek:;) ... wait a minute, how do trees possibly cost that much - you can usually get 3 for a tenner at Aldi in spring, guess someone's in for a windfall then (& that's cash, not apples!) ..

No doubt they have a Tory mate who needs a bung. Tory mate has trees at £10 each, competitor has trees at £3 each, who gets the contract? :rotfl:

Ben84

Martyn1981 wrote: »

Energy networks prepare to blend hydrogen into the gas grid for the first time



I thought hydrogen was already being blended in upto 5%?



Is that a reference back to town gas?

Town gas was a mix of hydrogen and carbon monoxide - hence it being poisonous.

I'd be very curious to take part in a trial like this - I like trying new stuff, but also I'd have concerns.

For a start, per cubic metre, hydrogen has less energy than methane:

https://www.afdc.energy.gov/pdfs/hyd_economy_bossel_eliasson.pdf

Page six, figure two shows the difference. The report says "But at any pressure, the volumetric energy density of methane gas exceeds that of hydrogen gas by a factor of 3.2"

So, as gas is delivered by the cubic meter, by my calculations suggest a 13.75% reduction in energy delivered per volume:

20 / 3.2 + 80 = 86.25

So, now a cubic metre of gas delivered to your house has only ~86% of the energy it did when it was all methane.

This raises the issue, will you still be paying the same price?

Also, gas appliance will have reduced output, since they're pressure regulated - my meter has a pressure regulator, so does the cooker and boiler (perhaps all gas appliances have them?). On 20% hydrogen my 15 kW back boiler is now about 13 kW. In this cold weather, with an older less powerful boiler, that would could increase an already existing problem heating a house, and where boilers are borderline it could put them in to a range where they can't keep up with a building's heat losses in cold weather. To be fair, most people's heating cycles on and off, so there is room to even it out with longer on cycles, but before we insulated our house, in winter, the boiler was usually running flat out for hours to keep up.

I haven't calculated the difference in air consumption - which relates to how much air is taken from the house by open flue appliances and sent up the chimney - effectively sucking the air you're trying to heat out the building and pulling in cold air from outside to replace it. Is this 20% hydrogen gas burning the same or more air from the house? If so, that's another efficiency hit.

I still like the idea of hydrogen fuel, but not unless the price per m3 is adjusted, and it could be a problem having your boiler's heat output reduced like this for some customers who have poorly sized boilers and/or high heat losses from their house.

Martyn1981

That's interesting hadn't thought of much of that.

But regarding this point:-

Ben84 wrote: »

So, now a cubic metre of gas delivered to your house has only ~86% of the energy it did when it was all methane.

This raises the issue, will you still be paying the same price.

Your gas bill should have an adjustment on it somewhere to take account of the 'calorific value', I think it'll give an average over the period, and it gets tested regularly(?)

So if the blended gas has less energy, then presumably that'll be reflected in the calorific value adjustment. But I'm completely guessing here.

Martyn1981

NigeWick wrote: »

That's what Ecotricity is starting with their gas from grass plants. They reckon that grass from marginal land could supply 80-90% of our gas requirement. Now if all new builds were really well insulated......

Hiya. The 97% of domestic gas that Ecotricity believe they can produce is after taking into account efficiency/insulation.

On this subject, I actually got in touch with them to point out that their suggested use of

A 5MW Green Gas Mill could supply 3,500 average homes (based on current consumption rates) and would need around 1,200 hectares of land, or 1.7% of the land within a 15km radius of the anaerobic digestion plant.

didn't add up, as they'd need more land than the UK has. I asked them this, amongst other things:

I note that Ecotricity says that it could theoretically get 97% of domestic gas demand from Green Gas Mills, and that this would require 5,000 mills. The info also states that each mill needs the grass from 1.7% of the land in a 15km radius. However, the area of land in a 15km radius circle is 707km2, so 5,000 such circles would need 3.5m km2 of land, but the UK only has 0.242m km2, or approx. 1/14th of the required area.

So I asked if areas would be shared by more than one gas mill. They were really helpful and replied with this:

Hi Martyn,

Thanks very much for getting in touch and my apologies for the delay in response.

I’ve been in touch with our green gas team who have offered the following responses:

- We suggested that 5000 x 5MW green gasmills would supply 97% of future UK household need for gas, whilst creating 75,000 jobs and pumping £7.5 billion into the rural economy.

- Yes, you have the maths right… if we were to build out such a vision there would be overlap into each green gasmill’s 15km supply radius.

- To feed 5000 x 5MW green gasmills would rely on 15 million acres (6 million hectares or 6000km2) which equals 24% of the total land area of the UK.

- If we were to use solely existing grassland to feed all 5000 of the green gasmills this would equate to approximately 60% of the total grassland area of the UK (according to defra stats there’s over 10m hectares of grassland in the UK).

- However, we would also like to incorporate the introduction of a grass break crop into the arable rotation in the form of herbal leys which will be in place for two years or more. These would be cut 3 times a year and fed into the green gasmill. Herbal leys have so many benefits for soil health which is in desperate need of improvement throughout the UK. They would also help alleviate problems such as herbicide resistant black grass which now affects approx 1.2m hectares of UK farmland causing major yield losses in wheat. The follow on food crop would also really benefit from this!

- For example, if we were to plant 1.4m hectares of grass break crops on arable land (20% of UK arable land) this would feed 1400 x 5MW green gasmills and equate to approximately 50% carbon sink over current practice having a very positive environmental impact!

Any more questions do let us know.

Overall, I think the idea is brilliant, and I love the fact that they are applying for licences wherever the fracking industry applies. Their idea certainly sounds viable, and I assume they've done the maths.

Martyn1981

Some more good news. I've often posted about cheap PV in India, and how diverting Indian investment from coal to PV is such an important and timely move. But of course PV alone is not a solution, so nice to see that wind contract prices are falling fast in India too.

Wind Energy Tariffs In India Fall 30% In 10 Months


In the longer term, the countries with the cheapest energy will probably become the worlds manufacturing base, so the poorer countries in S. America, Africa, India and southern Asia, may well become the richer nations. Rather ironic!