Future Firewood Demand Optimism?

[openspaceman]

1 hour ago, Paul in the woods said:

Also wondering about some form of biodigester to make some biogas.

What will you feed it with?

 

I think a hydro scheme is still your best bet

[Paul in the woods]

I've always thought it would make sense to recycle human waste via composting and then on to young trees, so human waste. II gather that may not produce much gas though but I can source an endless supply of cow manure, if I could be sure that was free from aminopyralid type weed killers that would be ideal.

 

Actually, I think wood backed up with solar for autumn/spring/summer use seems our best bet. Hydro more of a long term prospect for when I get fed up with processing firewood.

[Billhook]

Human waste needs a good dose of Batemans XXX to produce the amount of gas you need!

[openspaceman]

2 hours ago, Paul in the woods said:

I've always thought it would make sense to recycle human waste via composting and then on to young trees, so human waste. II gather that may not produce much gas though but I can source an endless supply of cow manure, if I could be sure that was free from aminopyralid type weed killers that would be ideal.

Yes it makes sense but most of us are plumbed into the wet sewage system, mostly for historical hygiene reasons, which means most of the fertiliser value goes out to sea. The solids do get put back on the land but there are issues with heavy metal contamination as there is no way of separating other wastes, like run off from roads, yards etc. from the crap and piss.

 

Even cow slurry is not that rich  as a feed stock; what it is good at is supplying the bacteria that have evolved to be in the hot, oxygen free, wet stomach that live on volatile solids produced from the food the cow eats and respiring methane and water.

 

So if you want to produce biogas you need a warm, anaerobic soup of food and fibre and inoculate it with fresh cowshit.

 

Maize silage is a good start but precision chopped grass silage is good too so is sugar beet.

 

Basically the best feed for the gas production is the same as what the cow would eat. That is not to say there is no beneft in adding shit because that will produce some gas but the main benefit is in reducing the pathogens in it before returning the digestate to the land.

2 hours ago, Paul in the woods said:

 

Actually, I think wood backed up with solar for autumn/spring/summer use seems our best bet. Hydro more of a long term prospect for when I get fed up with processing firewood.

yes, it looks like solar PV and battery will supply all my electricity needs for March through October but that still leaves a shortfall November through February. Wood does the space heating

[Paul in the woods]

We have a couple of acres of very rough pasture that could provide a feedstock. I also wonder about all the waste silage that's left to rot in the farms around here. There's a few wrapped bales rotting just down the road.

 

As for the human waste, no mains sewers round here, or water, or gas. Some of the locals still look surprised when you turn on a light...

 

The fields are frequently spread with sewage sludge which gets washed off into the streams and out to sea. I don't think I'd be causing any problem with a little domestic spreadding.

[devon TWiG]

1 hour ago, Paul in the woods said:

We have a couple of acres of very rough pasture that could provide a feedstock. I also wonder about all the waste silage that's left to rot in the farms around here. There's a few wrapped bales rotting just down the road.

 

As for the human waste, no mains sewers round here, or water, or gas. Some of the locals still look surprised when you turn on a light...

 

The fields are frequently spread with sewage sludge which gets washed off into the streams and out to sea. I don't think I'd be causing any problem with a little domestic spreadding.

I am pretty sure sewage sludge is not just spread on fields but injected below the surface to prevent run off , AD residuals are the same as well I think , it also allows grazing / cropping of grass to begin sooner ... farmers do not feed their cattle on contaminated crops ...

[Steven P]

Hydro - look to 'old fashioned' water wheels and the race to get water to the wheel - a pool upstream with a weir and a sluice gate to one side - open the sluice, water flows to the wheel. If you own 1 river bank, is there anything to stop you creating a pool / widen the stream on your side dug down a bit and take water off from that (pipe or a 'race') - hydro is all about the head of water, don't need so much water if you take off the supply high enough and pipe it to your turbine. Hydro like this is good, as long as your pool is a big enough store for the dry spells then it is constant, day and night

 

There are digesters out there that will harvest methane from slurry and silage I believe, not sure of their costs though

[openspaceman]

1 hour ago, devon TWiG said:

I am pretty sure sewage sludge is not just spread on fields but injected below the surface to prevent run off , AD residuals are the same as well I think , it also allows grazing / cropping of grass to begin sooner ... farmers do not feed their cattle on contaminated crops ...

Yes, I have not kept up with the legislation but it remains a hazardous waste and rules have to be followed for spreading on land. Twenty or more years ago the water companies invested in Short Rotation Arable crops to provide a non food outlet for the sludge but I don't expect many farmers are still involved in growing it.

[Paul in the woods]

There may be rules but that doesn't mean they are followed. Farm slurry should be injected but old equipment can still be used to spray it so that's what's done round here. 

 

The sewage sludge has most of the water removed and is dumped in piles on the fields for a month or two. It's then spread using the same trailers that spread rotted manure, so just thrown out the back. It's mainly done before planting crops, such as forage beet but I've seen it spread on grass. (Obviously animals are not put in the fields immediately afterwards but I think it's only kept animal free for a month or two). There is plenty dragged onto the roads etc so possibilities of cross contamination.

[Chalgravesteve]

On 24/04/2022 at 11:08, Steven P said:

Hydro - look to 'old fashioned' water wheels and the race to get water to the wheel - a pool upstream with a weir and a sluice gate to one side - open the sluice, water flows to the wheel. If you own 1 river bank, is there anything to stop you creating a pool / widen the stream on your side dug down a bit and take water off from that (pipe or a 'race') - hydro is all about the head of water, don't need so much water if you take off the supply high enough and pipe it to your turbine. Hydro like this is good, as long as your pool is a big enough store for the dry spells then it is constant, day and night

 

There are digesters out there that will harvest methane from slurry and silage I believe, not sure of their costs though

It depends what happens to the water after it has been "used" by the wheel and you probably need permission from The Environment Agency before you divert any water from the river. The current restrictions are any volume less than 20m3 per day is unlicensed, so you have to be able to control the flow of water into your "pond" to be less than that in any 24 hour period. However, if you are returning the same volume of water to the same river further downstream, then you are simply diverting the water, not abstracting it. If you don't return it to the river then it is abstraction and you will need consent once you abstract more than 20m3 (which wont run a water wheel for 24 hours!) in a day.

 

In order to have the head of water at the top, and still be able to return it to the same river further down, will require quite a bit of frontage as if you are dropping the water by 4/5/6/ft or more, then the river has to drop by the same height for you to get it back in there.

 

The reason why you cannot just abstract from a river that is passing your doorway, is that when you take water from the river at that point, you are denying that resource to someone further downstream who may already have a license. There are lots of regulations and hoops to jump through with the EA.