Dawn breaking over the flare and digester 1 as we do the composition testing on the gas intake to the engines

Dawn breaking over the flare and digester 1 as we do the composition testing on the gas intake to the engines

A nice early night last night meant a full eight hours before the alarm this morning which was bliss. Today was a fairly varied day all in all. There was a ground frost this morning which meant that Thorsten and Georg were devoted to trying to muck-spread while the ground was hard enough to hold the tractor and 19 tonne trailer. There hasn’t been a single snowfall this year and few frosts so there have been few opportunities to get the gulle (nutrient-rich digestate end product, effectively liquid manure) out on the fields over the winter which is important for a few reasons. First, spreading the digestate end product provides nitrogen, phosphorus and calcium reducing the need for (and cost of) conventional fertiliser. Second, this process closes the nutrient cycle (which is important for the sustainability of biogas). And finally, the enormous tank where the end product is stored was at least 80% full and once it’s full there’s no way of storing the digestate, and no where to put it!

Inside the digester during agitation. Looks like a Martian (or otherworldly) landscape apparently...?

Inside the digester during agitation. Looks like a Martian (or otherworldly) landscape apparently…?

Up to mid-morning we steadily got on with our testing and routine tasks while service engineers maintained one of the gas engines to ensure optimal efficiency and in preparation for upcoming emissions testing. Following the frosty early start, the day turned into beautiful sunshine in a cloudless sky and the PV installations in this part of the world started gearing up to donate to the grid. Thorsten dropped by around mid-morning to see whether Tim and I wanted to join him for some muck spreading as there’s a spare seat in the big tractor so we split the time and while I finished off that series of tests Tim helped fill the spreader and went about videoing the spreading in action. I got a similar slice of action later on and can understand why Christian enjoys muck-spreading so much. It’s thoroughly relaxing to switch on the radio, key in the range to which extend the spreader arms, set the cruise control on the tractor and give a decent amount of field (about 0.7 Ha) a nice wet brown covering before using the ipad/ ipod linked to the GPS tracker to check the field off of the schedule for the day. Yes, there really is that much technology in these tractors!

During a couple of spreading visits Thorsten told me of the importance of diversifying what is grown to spread the risk for crops (last year was terrible for corn but nearly a record for wheat – I think I’ve got that the right way round – on account of the amount of rain and when it fell). It also turns out that the farm is entirely plough-less which surprised me. Not that it was something I’d ever thought about in depth, I admit. It turns out that ploughing is highly energy intensive, kills large numbers of soil fauna and also oxidises the soil requiring a deeper humus layer. On the farm they tend to grow mustard instead during the off-season to control weeds and then when the frost comes it splits the bulbs and the plants die back returning all of the nutrients to the soil which is then rotavated instead before planting. See, not just biogas that’s being taught out here – to be honest I could write a tome on all of the odds and ends I’ve learned in a week out here (and several more on the now known-unknowns that have come to my attention – like why when you dilute digestate of pH 7-8 with distilled water of pH about 7 does the pH of the solution increase to about 8.2 when the digestate is already about 92% water?).

Back for lunch of baked rice with courgette and fennel and green salad which was delicious and topped off by a nut cake of which I had two pieces. I’ve been starving all day and am now going to blame it on the doughnut I had with breakfast (yes, that’s three pieces of cake by lunch time) that was made with a little bit of milk that didn’t really agree with me. (Nothing wrong with the doughnut, which was very tasty, just a bit wrong with me).

As another week’s worth of silage has now been fed to the fermenter there was some shovelling to do to get the remainder off of the ‘sausage’ of corn in the side of the silo. So, we set to that to work off some of the lunchtime calories before getting stuck into the afternoon’s routine.

Tim is king of the maize pile. Oh, and the white thing next to him is the 'sausage' of corn

Tim is king of the maize pile. Oh, and the white thing next to him is the ‘sausage’ of corn

Around 4pm Thorsten asked whether one of us was free to help him lift some boards for one of his friends. I jumped in the car with the friend and spent the next few hours unloading plasterboard from a forklift truck through an upstairs window into the newly built flat his friend has built on top of his girlfriend’s house. Now, when I say on top, I really mean it – they took the roof off, added a spiral staircase next to the front door and installed an entire other floor on the top of the house with the structural work taking about two weeks. Yes, two weeks! The additional storey is constructed entirely from wood and was largely made offsite and then clicked together in place and, although still work in progress, it looked great with high, vaunted ceilings in the eaves of the roof and loads of light flooding in through windows galore. Even though my fingers were now tingling from hefting pallet full of plaster boards – having not entirely recovered from climbing at the weekend – it was nice to have been able to help out a little bit and also great to see how the community here is close enough to help each other out (Thorsten picked up the pallet of boards from a storage yard with the forklift and drove it through the town to the house because he was asked if he could help while at dinner last night). I asked him about this and he said that the guy we helped was really good at exterior painting and woodwork so he’d just call in the favour if he needed some help in the future; isn’t that the way communities should be?

Back for dinner where I’ve got humous and tofutier (fake meat and vegetable) spread to cover the rye bread with before retiring early for a bit of diary writing and perhaps a little work too. Or maybe just preparation for work; we’ll see how tired I feel after this…



Meet Thorsten 6:30 and he shows us around the AD plant and takes us through the process. The first thing to do every day is visually check all of the digesters for the level, whether they’ve a foam capping and that the pumps aren’t flooded before checking there is a temperature difference across the activated charcoal H2S filter, which indicates it’s operating. Once these checks are complete, then it is breakfast. Today with all of the explanations, I think we were a little late (around 8).

After breakfast the first job was with Christian, who is the only non-family member that works on the farm full-time. We have to peel the covering for the silage back which involves lugging some pretty heavy sand bags across a pretty slippery tarpaulin on or near the edge of a 15-20ft pile of shifting silage. It’s not as bad as I first thought though, even if carrying the sandbags up to the middle of the pile is a bugger as they just drag you back down towards the side. While I’m on top of the pile Tim gets stuck in with the shovel moving a hefty amount of silage that’s fallen down the crack next to the corn which is bagged in a sausage (Thorsten’s description, not mine). Christian and I first re-secure the covering and then move on to rolling up the netting. Christian seems a good character and despite both only being able to understand a little of what is said we manage to coordinate the nets and he shows me the three different kinds of poop on site, including the freshly delivered chicken. Surprisingly they don’t smell too badly. Honest!

Yep. That is a lotta...

Yep. That is a lotta…

After this I grab a shovel to help Tim finish moving the silage and then after a good amount of shovelling, making us feel like we’ve earned it, it’s lunch. Mittagsessen for the veggies is spaghetti with spinach, onion and olive oil, which I thought was pretty damn tasty especially with a walnut cake for dessert.

After lunch we start on the measurements in the laboratory that Thorsten has built, but a representative from the gas analyser company arrives and we join while he shows how it works, and we get to play too.

The fermenter...it's pretty big!

The fermenter…it’s pretty big!

Then we’re let loose to do the analysis (temperature, gas analysis, solid analysis, FOS and TAC) for the fermenter and the first two digesters/ storage tanks (nachgaerer). This takes the remainder of afternoon but we finish it with some time to spare before dinner so a necessary shower is taken before we sit down with the family again.

For dinner we have the choice of more spaghetti or rye bread with cheese/ jam/ meat which isn’t much of a contest for me really. I mean, the rye bread here is pretty special but who wouldn’t want spinach. Oh, spinach spinach spinach. Oh, and the pasta was with salad too – wouldn’t want you thinking I was deprived of my greens while over here.

After dinner I managed to catch up on a few emails to maintain touch with the homeland but it didn’t take long for the effects of the long day to set in and soon I was curled up on my air bed which is surprisingly comfortable. What is about Germany, why is everything better here?