Making the best of Global Warming

[Joules]

Been away from the forums for quite a while, busy playing with my peddle car and other stuff.  I put some extra solar panels up on the wife's Studio/Shed a few years back using both sides to make better use of afternoon sun.  It didn't perform as well as I had hoped especially during winter months.  Don't get me wrong it did produce, no longer needing to top up the battery during winter just to keep it alive.

So, onto Plan B (sub project 359) installing a tracker mount in our urban garden.  Not a huge amount of space and with fencing and buildings around, could be a bit challenging.

New project, start with a big hole, serves dual purpose if project goes tit's I have somewhere to bury it.  The tracker used is a commercial one from Eco Worthy, I just couldn't fabricate it for the cost !!!

Get measuring the base and work out hole positions, as it is supplied with 10mm expansion bolts for drilling into your concrete slab.   Hmmm, sod that, it needs to be able to survive earthquakes and tornadoes.

I fabricated an M12 stainless steel frame with 3D printed spacers for the whole lot to be cast in the foundation.  A template was cut for the hole pattern as the tracker base was not symmetrical (correct spelling), laser cut out of card, this being the third attempt.  It was used for spacing the holes in the 3D printed rings holding the stainless steel studding.

The actual supplied tracker mount was of course modded, to improve fit and finish plus shim for bearing surface to remove slop.  It has no quality bearings and not expected for the price, but it has room for improvement.  I am putting a smaller array than it is designed for, keeping the loading and area reduced should allow it to function longer in windy conditions.  It is supplied with sensors for tracking the sun and also monitoring wind conditions so it can go level if gusts start to pick up.   One fly in that idea is the fact it goes to an extreme location, before motoring back to level on an estimated time, not great if the wind has picked up, plus the location I would fit the anemometer would be quite shielded.  So we level it manually based on conditions and forecasts, it really produces a lot of power just looking straight up.  We don't need it tracking every day so it is lashed level with rope that also acts as shock absorber in windy conditions.

Finally got the tracker installed after wife and me mixed about 800kg of concrete in a large plastic bucket....  She's a keeper....      All the frame work above the tracker is modified from that supplied and fitted with 100W panels as they are manageable as I get older.  The added benefit of a tracker is being able to keep the panels clean and free of snow.

At last fully installed and producing power, better than I had hoped for on a bright day and installed a few weeks before the current UK heatwave.   Great, more power for tools and toys....  Uh oh, wife bought an air conditioner for the dog (long haired Shepherd)  The air con is now run off the tracker mount, both wife and dog very pleased...      Not my intended use, but hey I get to use more power outside of crazy hot days.

 

[awemawson]

That footing and bolt circle look more like the gun mounts found along the south coast for repelling unwanted  visitors in 1939-40!

[Joules]

I hadn't considered a mini gun Andrew, but now you mention it.  Keep the pigeons and other vermin at bay...

[AdeV]

Oooh, that's swish!

Might I ask where you got it from?

I should really learn to read posts properly & then I wouldn't look quite so stupid answering the question you already answered!

I'd quite fancy one of those in my garden... Also, given a sensible sunny day & not baking hot, what sort of power are you getting from it (instantaneous & over a good day)? I'm guessing you don't have any winter readings yet, given you don't live in Birkenhead  , but I think that's when the tracker will really come into its own.

BTW - that's a pretty damn competitive price sans panels... very tempting!

[vtsteam]

Wow, very nice Joules! 

Now you just need a thermoelectric panel behind the air conditioner. 

[rleete]

Doesn't it block access to the door for the shed?

[awemawson]

I hadn't considered a mini gun Andrew, but now you mention it.  Keep the pigeons and other vermin at bay...

As it happens due to an invasion of crows who eat more feed than the chicken, I'm resurrecting at the moment a propane fueled 'crow scarer'. Cunning device slowly inflates a small reservoir of propane with a diaphragm lid that lifts a mechanism that toggles and discharges the gas into the 4" diameter 24" long barrel and then clouts a piezo element sparking to fire the charge. Throtle valve controls the rate of cycling. It makes a massive bang when it fires Currently awaiting more neoprene as the diaphragm needs replacing before I put it back together.

[Joules]

You're only one step away from making a buzz bomb Andrew...

Careful measurements were taken to clear Studio and also work out best position for winter sun, based on the x8, 100W panels we have.

I am currently seeing 750W an hour for at least 4-5hrs (sunny hot day), after around 4-5kW all our batteries are full  so don't have a true
amount for how much the tracker can produce as it gets throttled back.   These last few days not even activated the tracker as it collects enough just pointing up.  I think we produced 20kw for the air con during these heatwaves.

The array is 2m x 2m to give it some scale, so not far off 20% efficient, considering our latitude.

[vtsteam]

Joules, what do you have for a battery, and what does it power?

[Joules]

We have a 12v Rolls battery that's covered by the workshop and Studio array.   That handles  fridge and freezer plus most of our IT gear.  The tracker has ended up powering our Bluetti (7.5kW total storage) power station.   That pretty much covers all kitchen appliances, microwave, the air con and any other heavy loads up to 2.5kW.   I run the lathe and mill from the Bluetti as well when we have plenty of power.   House is still grid tied as never enough in winter, but March through October the house only uses 1-2kW a day.   We don't sell back to the grid and using the Bluetti solves lots of regulation issues having solar dedicated wiring in the house.   Pretty much just electric shower and electric range cooker only loads we can't power, wife likes to bake, so well worth the power used.

The Bluetti can handle a direct feed in from the tracker and make full use of the array.  The 12V side maxes out at 600W per array, looking into moving to 24V replacing the Rolls battery. This is as much a hobby for me these days, it certainly isn't a fit and forget system.  My workshop rack is a lot of work compared to the Bluetti.  The all in one is very convenient, and portable, I would certainly say it's the way to go if you are starting from scratch.

Apologies for the awful picture of Bluetti stack, AC200L and two B300K expansion batteries.  Wife really likes this system and took to using it straight away.

[Joules]

I was very wary of spending that amount of coin on a Bluetti system  especially considering the YouTube shills promoting it.  I started  by getting an AC180 to run our winter paraffin heater and media PC.  Later got an AC50B and that now runs a Windows laptop and solid state laser cutter, by this point I was pretty impressed.  The AC50B was actually bought to replace an old APC UPS, but found it could do much more.     seems I am now a Bluetti shill....   The Bluettis can all be grid charged, or in our case, charged via an inverter from the 12V system we already had.   The big Bluetti can be charged from the tracker and a programmable limited grid supply, so it won't kill our 12v system.  Upto 750W off the tracker and 250W coming from the other system, doesn't take long to fill up, and it does pass through charging so the power coming in can go straight out to other loads.

I have already sold off a couple of generators we used to have, the AC180 replaced a portable Honda I'd kept for 30yrs+   No more storing oil and petrol, especially the bio yuck you get nowadays.

[vtsteam]

That's really interesting to me, Joules. In the 90's I lived on a houseboat that I built, and traveled 1700 miles in down the US coast and across Florida. I had a Heart Interface 1200 watt inverter, and unfortunately a small noisy Coleman generator for when the 25 hp outboard motor wasn't running and charging. Three 90 AH deep cycle 12 V batteries. I lived on that boat, off and on, for ten years. It served as a basecamp here on our land while I built our present house 25 years ago.

I would have loved to have had photocells and a more modern storage and inverter system like you have now. I did make a hot water solar collector for showers. I found that 12 V lighting and appliances were useful on the boat back then. The inverter had a charger in it so if I ever did spend the night at a marina, it would transfer switch over automatically and charge the batteries.

Now I do think about alternative power, so it's interesting to see how much more efficient your system is than anything I ever was used to. And how little space your array takes up for that amount of power. We do heat with wood (we live on 67 acres of mostly forested land) and one of my interests in Stirling engines has been with the ultimate aim of making something big that, in the frequent power outages we have could serve for some power. Although for continuous use, photocells make more sense. Both would be ideal. Actually a Stirling would make sense for CHP since we heat with wood.

I'm obviously a long way from producing usable amounts of power via a hot air engine. But I do think it's possible. Well also, I have to admit, building a big Stirling would be fascinating and fun. You have to add in the fun factor in anything, I think.

I still do have the Heart Interface inverter but it stopped working. I think the output power transistor(?s) is the problem but I am not knowledgeable enough about electronics to troubleshoot it. I can solder well enough and once built an LNW-80 computer from scratch - bare boards and ICs etc, but analyzing circuits, nope.

[Joules]

Totally agree on the fun factor.   I just added the final sensor to the tracker, its anemometer.   Pretty useless in these surroundings with buildings and fence.   However it has to be located where footballs have the slimmest  chance of finding it.  The tracker is currently set in storm mode as winds have picked up, so it is lashed.  The anemometer is barely spinning, I do a weather check in a morning before deciding to release the tracker.   It still produces a decent amount of power like this.   I did follow the New Zealand Whispergen for a good number of years, sterling CHP

Power in the UK not quite as bad as your situation, but it certainly could get that way with the state its in.   Electric companies here are worried about the number of people having off grid systems and not paying their extortionate prices for power.  We have plenty of redundancy, the tracker is a gamble to see how it performs over a year or two.   With more space it's a no brainer to go with more panels ground mounted.

We have solid fuel heating here, with Japanese paraffin heaters for colder evenings and days that don't justify the stove which does our hot water and central heating.   No hot water in the summers, been like that for 20yrs+, have a couple of Kelly Kettles we use for washing up.   Washing machine heats its water and we run it off the Bluetti.    Things have come along way since I set up a small panel in a bedroom window many years back before the roof top solar craze to see if it was worth trying.

The workshop solar has been a continuous work in progress, soon to have a major update.

[vtsteam]

I like seeing the pictures!

re.wind furling. I was thinking about self steering rigs for ocean going sailboats. In the olde days (like 70's) mechanical self-steering co-pilots used a weathervane to turn the tiller to correct the course. The problem they found was it took a fair degree of deviation from the course to apply enough power to correct the steering. Then someone figured out that instead of a vane with a vertical axis, it was much more effective and powerful to mount the vane with a horizontal axis at the bottom. When the boat turned off course, the whole vane flopped over until it was horizontal, at which point it spilled the wind-- a far greater range of motion than the correction angle of a vertically pivoted fin. These were quicker reacting and stronger as servomechanisms.

I don't know if any of that has application to your wind situation. Maybe a finned switch on a horizontal axis for operating the furling servo. Or a purely mechanical system of furling. it's too bad your present system first tries to limit in the wrong direction, but I'm sure you'll eventually make something to solve it.

[Joules]

A half circle cam with two microswitches so the controller knows it is East or West facing, then motor till both switches are zero hence level, would be nice.  I'd still be lashing it up in bad weather or leaving it unattended for any length of time,  so really it will do as is.

[AdeV]

Just looking at Eco Worthy's website again.... Their solar tracker thingybob + 6x 195W panels is coming in at a hair under 72p/watt capacity! That's bonkers! The last (and, indeed, the first...) solar panel I bought was nearly £1 a watt just for the panel alone, without any other gubbins to go with it, although that was a few years ago now. In fact, a single 195w bifacial panel is rather cheaper than the 100W monofacial panel I bought back then. Honestly, it feels like I've blinked, and the bottom's fallen out of the market!

Definitely going to be looking at one (or more, depending on garden size!) of these next year.


 

Speaking of heatwaves.... (we're not having one oop north right now!  ); I believe solar panels lose efficiency when they get hot, which is always a pain as the best sunshine usually comes with a lot of heat too...

So then I got to thinking - which is always dangerous  - in Ye Olde Days (1970s and earlier) one could have "solar panels" on the roof, but they were thermal panels, not PV. i.e. they warmed your water up... My grandparents had one on their roof for donkeys years... although unfortunately they died & the house was sold long before I got interested in this stuff.

However - I got to wondering: How hard would it be (famous last words!) to create a hybrid PV/hot water panel? i.e. make a normal thermal panel (lots of black-painted copper pipe in a think black box); but instead of putting a glass front on it; put a solar panel on it instead! Now... obviously the panel's going to eat a lot of the potential heat; but since it's going to get hot, wouldn't the thermal panel underneath suck out a lot of that heat? Which could then be used to pre-warm a tank of water - and, given that heating water is one of the most energy intense things we modern people do, wouldn't this save some energy (In summer at least!) by a) using the heat energy, and b) making the panels even more efficient than they already are?

Sadly, winter is going to be its usual problematic self, with bugger all sunshine at low angles & low temperatures limiting any available heat (and one might need to deal with freezing temperatures too)... but I do wonder if, for those hot summer days, it might be an interesting system at least?

[vtsteam]

Ade I worked for a thin film optical filter firm, and they were getting into solar cell tech at the time. I suggested something similar, except not hot water, a thermoeletric cell integrated under the photosensitive cell with a heatsink on the bottom. The thermoelectric cell works on differential temperature. Efficiency of a thermoelectric cell is lower than a photocell, but it's waste heat anyway,  it adds additional output, and the cooling of the sink helps the photocell's efficiency which drops with increased temp, so the increase could be decent.

Also since there is no water, no freezing problem, and even in winter there is a temperature differential.

No interest.

[Joules]

Ade, I can tell you at the height of the heatwave the array was most likely only 50W down on its max capacity, won't know till a bright sunny cold day for sure.  I use a thermal camera to survey the panels during the day, it is also used on all wiring and equipment to watch for issues.  Picture attached was the hottest day we had and actually had a fuse holder melt on the workshop rack for another device.

We still generate power on overcast days, might only be 10% of the arrays power, but every little helps keep grid charging at bay.   We bank power using the storage and try to use what we have if we know we can get more over the next few days.  Can be a tricky balancing act but we gradually got a system that works during the winter.  Quite often after snow and you get a sunny day, clean the panels as quick as possible as reflected light gets bounced back strongly by a bit of cloud or even the snow itself.  It probably helps that it's just the Mrs, me and the dog and we don't own a TV, so no constant drain on our system.  We use RV fridge and freezer, that help rotate food more quickly, but also means we can move them into the conservatory where it's cold in the winter so their energy demand goes way down.   No worries in summer as we usually have way more power than they need, but we move them into the kitchen where it's shaded.