A page on my website regarding renewable energy......nothing to do with organbuilding? Well.....I would say it has many similarities. Like the wind in a pipe organ, electricity and water have much in common. It needs to be produced, stored and distributed in due course. For example in an organ we store air at pressure in the bellows (or reservoir)......not much different with water in the attic tank or electricity in batteries. There are many overlapping principles too......pressure (volts), resistance (ohms), power (watts).......and the quantum of all these expressed in terms of real ability (amps).
And then of course I need a working knowledge of electricity when it comes to organs......especially the difference between DC (direct current) and AC (alternating) and how to deal with them. There really is soooo much to know!
It's appropriate too, with minding organs, that I have a working knowledge of heating systems and the effect on environment within a church or wherever.
And finally, like building an organ from scratch, logistics and planning came into this. (That doesn't include the fact that we erected the turbine on a day when there was a yellow wind warning! We were lucky to get an hour of relative calm.)
And so....where does one start? I'm not being smart when I say at the beginning! I suppose that raises the question why? For me.....partly because I can. Secondly I'd be conscious of the environment.....and also of course I like to be efficient. And in fact these two considerations usually lead me to the same conclusion.
I'm directly interested in the topic as a whole when it comes to maintaining pipe organs dating back well over a century.....they are sensitive things and can react badly to an ill-judged heating regime.
And I'm indirectly interested, for I might well diversfy into this.
Here I had an ideal site, with good exposure to the wind and sun (by chance that 40ft container faces south). A small bit of research with our met office confirmed there was an ample supply of wind. (I was already privy to good sun performance due to the thermal solar panels I fitted on the house roof many years ago).
I suppose the next step was to choose a supplier. After much research I settled on a company in Mainland China: Qingdao Allrun New Energy Company. This turned out to be an excellent choice and they have been exceptional in their after-sales advice. My thanks to Liyan there for this.
Whilst thanking people, my gratitude goes to Ken McCarthy of Amppower in Nenagh - he guided me throughout, giving me the necessary confidence.
Alongside this I had to decide what I wanted to achieve.......on-grid or off-grid? Well, the latter brings many troubles that I can happily live without, so off-grid was my choice. The next thing was to define what I wanted to do. I settled on a modestly sized system for two main reasons. The first was considering the electrical load here (or any house for that matter). Yes, there are big users.....the dishwasher, washing machine, dryer......but these things are used infrequently compared with smaller appliances......I refer to things like lights, TV, the pumps for the thermal solar panels (these often run all day throughout summer), the pump for the sewage system, the fridge/freezer.......whilst none of these are big users, they all run a lot and this actually constitutes the bulk of the bill here.
My 2nd reason for a modest set-up was......well......I could have a large turbine and large array of solar PV panels.......but what then on days we have no wind or sun? By all means if one wants to go completely off-grid go bigger.....but then you'd also need much bigger ability to store electricity, and indeed a backup generator......
So I settled on a 2.2KW turbine with 550W of PV solar panels. Here's a funny photo with the blades appearing to be bent because they are on the move:
And here's the bits & pieces on the floor......
You can see above too, that the installation is heavily grounded to protect against a lightening strike. The whole is grounded no less than 7 times in different places using 10sqmm cable.
The solar panels are mounted on factory-made supports.......I have blocked off the sides and underneath to prevent the wind from catching them......there's quite a surface area there. (Panels measure about 7' x 4' each).
As they come from the factory they are intended to lie on a flat roof. They tilt them up to the tune of just 10 degrees. But when I looked into this, the ideal angle off horizontal is 35 and 74 for summer and winter respectively. And so I opted to mount them on the side of the container instead - here they stand at approx 60 degrees off horizontal.....a happy medium, biased slightly towards the winter ideal because (a) that's when I want the power more so and (b) the more upright they are the less likely to catch the wind. They are also less exposed to the wind here than on the roof. I could actually arrange to have them seasonally adjustable, but I don't think the (small) added efficiency would be worth the trouble.
The positioning for everything was an easy decision; the 40ft container was there already - it is used to store organs. It provided an easy platform, with the base of the turbine essentially gaining another 2 metres. Between this and the pole and the blade radius, it brought me to just under the 10M threshold, after which one needs planning permission - so that all worked out well. The roof also lent itself well to welding everything to it, including specially made cleats for the guy ropes:
Here we see the roof, showing the cantilevered support for the south guy rope (I'll give the whole thing a nice coat of rustproofing over the summer):
Here we see the fun of getting the turbine upright. It was quite something doing this manually, taking 6 men. I do have a scheme in mind which will allow me to take it up and down single-handedly.......I'll do this when the turbine first requires inspection (infrequent):
Along with the turbine Liyan sent me a control box and inverter. The control box accepts current from the turbine (3-phase AC at 48V) and the solar panels (38.5VDC) and sends a charge out to the batteries as necessary. The large green resistors are basically heaters which will dump excess energy if required......this protects the batteries against overcharging:
And here we see the inverter - its purpose is to convert 48VDC to usable 240VAC for use in the house. I like that this machine cuts out if the input falls below 44VDC.......this protects the batteries against over-discharging. The health of the batteries is vital to these systems......discharging or overcharging are both equally unwelcome:
And of course we need good batteries.....ordinary car or lorry batteries would be useless. They need to be what's called deep cycle.......they are more robustly built than car batteries. I opted for 225AH batteries, 8 of them wired together in series gives me the required 48V. These particular batteries are made with golf buggies in mind.......sometimes described as leisure batteries. The 225AH (amps per hour) number is interesting.....it is the rate at which the battery can run for a set period (I think that's 20 hours) before fully discharging. It's just a rule-of-thumb thing really, for comparison purposes, for different batteries will perform differently if the same test were to be applied for different durations.....
The sizing of batteries is all-important. One has to ask how much standby electricity is required....ie how many hours do you need to run with no wind or sun? This bank of batteries is generously sized, giving me a total of 11KWH.....eleven kilowatt hours. Put simply, this will power a 100W bulb for 110 hours. (Not that I use old incandescant bulbs......every bulb here is high efficiency LED!!). That's on paper. But then there are losses......resistance (voltage drop) in the cables.....the inverter will use something like 10% of what it converts.......and then of course batteries work less efficiently in cold weather......and also the system I'm running guards against heavy discharging, shutting the system down if battery voltage falls below 44v (whilst a slight nuisance, this will lengthen the life of the batteries)......so it's a big balancing act.......
I was fortunate to come upon Island Energy Solutions of Downpatrick, and Phillip there was most generous with his knowledge and time, so my thanks to him for coming up with the optimum solution, which looks as follows:
What I like about all this is it's easy to follow what's going on. All paramaters of incoming current, voltage and power are available, as is the condition of battery charge. Here we can see for example 534W coming in from the turbine:
And on the outgoing side I can measure with a meter - I left the incoming cable to the house easily available. Here we can see .6A being consumed. That would be about right, for the 2 thermal solar pumps and the fridge/freezer were running at the time......144Watts (240V x .6).....that's about right.....
2 weeks fitted and we have the first really windy spell. See below how the tail furls the turbine out of the way of excess wind to protect it. It was nearly dark, hence the relatively bad photo, but you can clearly see how the turbine has been swung to 90 degrees relative to the tail. I love this low-tech solution......really nothing to go wrong. (Hope that doesn't turn out to be 'famous last words'!!)
The other thing noticeable today with the high wind was how the turbine automatically goes into safety mode to protect the batteries from over-charging. Not only does the system have the ability to BRAKE the turbine electrically, but it also dumps current if required. I am impressed.
The trick now is how to use the excess (free) 2KW for the next day or so. The dryer here will easily run at that (it's a heatpump unit, rated at 800W - it gets an A++ rating), but alas not quite the washing machine, which peaks at 2.3KW. Could this be an argument for taking the jump to a 5KW unit? I don't think so, for while it's a generally windy site here, this high wind is just 3 or 4 times per year. I find the best thing is to size anything towards the average. We did this with the house heatpump (see below) and it worked out fine. I think if one sizes for all conditions, then things are ungainly and inefficient for much of the time.
(A 5KW set-up to me, would be borderline going off-grid. That's just my opinion.)
4 months in and I had an issue with the inverter. Not even my friendly and extra-patient electronic engineer (Martin Edwards) could solve the problem, so I went searching for a replacement. I opted for a European brand (Dutch); Victron because Martin was happy with the detail and it's sufficiently near to get advice and repair if necessary. I just as happy as it's more efficient (94% vs a max of 90% from the old unit). Furthermore, there is a dealer nearby (JTM Power) with expert knowledge in all things power related, and so that's reassuring.
So this is the new unit (on the right) it can cope with up to 1200W (peaking at twice that) - plenty for my needs:
This then communicates to the house via a Victron Filax changeover box. This means that when the batteries run low, the inverter cuts out to prevent deep discharge. At this point output ceases and the Filax senses that and cuts over to mains in approx. 4ms......fast enough for a TV or computer to continue to function. Once the batteries reach 50V the inverter automatically reboots and the Filax switches back to turbine power.
It's good to get this automated, because I'm running the fridge/freezer, solar panel (thermal) pumps and other sensitive things off the turbine.....ie if power fails, damage would result.
The final detail - a timer switch:
This is just so I can prioritise the use of the power for daytime, as mains day rates are over twice the price of night. (This is for times of the year, like now, summer, when the wind isn't so plentiful......and it's easily overriden in the event of a few lively days in a row.) I couldn't use an ordinary timer plug because, well.....the clock is run from the house mains, but the circuit I need to switch is the inverter, 48V......so this fuseboard mounting timer switch came in handy for the purpose.
And so this little kit adds nicely to an already efficient house here. These are the solar panels.....there wasn't a direct south-facing roof (still isn't!!), so we opted for a SW/SE configuration. At 6sqm they're generously sized for a domestic installation for this reason. It worked out quite well actually, for sometimes there is sun in the morning and not in the evening, or vice versa......
And the air/water heatpump.....this acts as the backbone to all hot water needs here from Oct - March (the solar usually does the rest of the year on its own). I have them sorted so they will only run at nightime rates, and only when the temperature exceeds 3 deg C. (It thankfully rarely falls below that.) This way I get a very acceptable 4.7 COP (Coefficient of Performance) at discounted rates. In simple terms this means for every 1 unit we use we are rewarded with 4.7 back relative to an ordinary heater....all at 1/2 price, making it 8 times more cost-efficient than a normal heater at the usual rates. And of course our supplier uses renewably generated electricity. (All the more reason to begrudge paying the monthly €6.70 PSO (Public Service Obligation) levy. This is allegedly for "security of supply and environmental protection". Yeah, yeah, yeah!! That there's VAT charged on top of the levy is a source of mystery to me too! Surely a case of double taxation(?))
The trick of course is to merge all this in with the multi-fuel stove and back-up oil boiler. It's not automated as such.......I have deliberately kept it manually adjustable, largely because in automating, it merely consumes more energy. Every zone valve for instance consumes several watts. Tricky too, was merging the stove (which must be vented for safety) to a sealed system.....that was.....interesting(!)......but despite what every plumber told me.....it is very doable ;-) Worth the trouble? I think so. I have used less than one fill of oil since installing the heatpump and solar 13 years ago.