M&S to Power 33 Stores with 19GW of Waste-to-Biogas Energy Production

[The Oil Baron]

Marks & Spencer (M&S) will send its food waste to an 60,000 tonne capacity anaerobic digester plant, where food waste gets converted to biogas, which is used to produce clean electricity, and the digestate that is produced is used as a nutrient-rich soil conditioner.

M&S will directly purchase electricity equivalent to 19,000 MW produced from the AD plant every year. The generated electricity is enough to power about 33 M&S stores.

[Ulrik]

19GW seems a huge capacity. I wander if there is an option here for other supermarket chains to invest in similar waste-to-biogas plants. Or maybe even hotel chains, or restaurants.

[Alan]

19GW seems a huge capacity. I wander if there is an option here for other supermarket chains to invest in similar waste-to-biogas plants. Or maybe even hotel chains, or restaurants.

Are we really to believe that each M&S store consumes 575 Megawatts on average? so if the store employs 575 staff that's 1 Megawatt per employee? I don't believe it. There must be a mixup in units somewhere and the numbers are being quoted without any understanding.

If he means 19,000 Megawatt-hours per year it makes more sense. That would be an average output of just over 2 MW which is believable.

[Ulrik]

I assume that the M&S stores which employee might employ as many as 575 staff will be the large mega stores, and they will never have all 575 staff in at the same time, so your theory of 1 megawatt per person is wrong.

On top of that, their is no mention that the 33 M&S stores are not small local stores, that have a very low energy demand.

But on top of all that is that fact that maybe you have actually got your units mixed up. In general people require several kilowatts to run everything they need in their daily lives. So 1MW is definitely enough to handle one employee, plus a few lights, and maybe a refrigerator.

[Alan]

Exactly . . in other words the original claim that 19 GW would be used by 33 M&S stores is ridiculous . . . you are making my point. There are no M&S stores using 575 Megawatts or anything remotely similar. 19 GW is about one fifth of the UK's total output of electrical power and to suggest that 33 M&S stores would use that amount of electrical power is ludicrous, really. The original post had no credibility.

My suggestion is that the figure of 19,000 actually refers to the number of Megawatt-hours (of energy) produced per year by this process. That is plausible because it would need a power generator working at an average power of about 2.2 MW. This is a fairly small power station and quite believable.

On checking via google the information is here:
http://renewables.seenews.com/news/m...s-plant-311186

. . and M&S will be buying 19,000 Megawatt-hours of energy per year from a company in Glasgow that operates a biomass generation facility, Shanks Group plc. That is an average power of 2167 kW (equal to 2.167 MW or 0.002167 GW) over the year.

[Ulrik]

Ah OK sorry, I thought you were saying that it was impossible for 19GW to supply enough power to run 33 stores; not that it was far too much.

[Alan]

Thanks for that. I was really saying that it's good to quote numbers, there is not enough of that, but they have to be right, or at least in the ball-park in this case both the original article and the quoter mixed up power (Megawatts) with energy (Megawatt hours) and the mistakes combined to imply that every M&S store needs the output from a large power station .