Hive Heating

[jezd]

I know Finman does this and others have discussed it on here, but does anyone run a system that heats several hives? are you just using heating cables? supply from battery or mains? thermostat control? solar panals used for charging?

so many questions!

Cheers

Jez

PS first snow due tomorrow bbbbrrrrrr

 

[Brosville]

I've no idea about applying heat to hives, but in renewables the general advice is to never try using battery/solar photovoltaic panels for heating - any form of electrical heating uses absolutely gobbets of power, and even to heat a single hive would entail an awful lot of batteries/panels that would be frighteningly expensive.
You've also got "sod's law" working to use solar panels for heating - when you most need the heat, the panels are picking up the least power

 

[oliver90owner]

Hi jezd,

I would think the answer is most likely no. BUT there may be one or two...one never knows. I have considered it but only from the mains, unless a battery had some form of recharging system (photovoltaic or wind turbine) and they would likely disappear, if in a remote location!!

And that was previous to Finman's recent postings. Never got further than that. As I said recently, perhaps I should consider digging up my earth warming cable from the bed in the glasshouse.

Each hive should already have enough embedded heat energy in the form of honey. Been OK for them for the last few millennia - but homo sapiens didn't mess around bringing bees, with bermuda shorts, close to the arctic circle!

Several hives would need several Watts, and more, so a battery on it's own would soon become exhausted - even a big one.

A control system would be needed for a battery, or it would soon be 'brown bread', and a thermostat for a mains system.

It will still come down to insulation, insulation, insulation as the cheapest way forward initially. The same as our houses.

I wonder what the rate of honey usage must be for the basic metabolic functions for a strong colony (never bothered to try to find out). Anybody know? If there were a saving of, say, 20 jars of honey per hive (10kg) that would go a long way towards paying for the energy used. Then feed sugar for expansion in spring as well.

Might be economic (profitable) as well as just a fanciful idea.

I can envisage it now - long rows of hives looking like igloos (covered in thick insulation) each with it's own umbilical cord with metered heat input and feed pipe to a sugar feeder (each with it's own level device) ready to (automatically?) increase the supply of sugar (and protein when rquired for brood production) as the springtime approaches.

The micro-computer in each colony would be able to monitor heat output from the colony and thus interpret this as brood production and make appropriate alterations to the micro-climate in preparation for the anticipated build-up to springtime honey production or pollination requirements.

There. How about that for a prediction? It would give all those commercial beekeepers something to keep an eye on, over the winter (if they were not completely redundant - bar a techniciaian to repair the faults thrown up by the auto-diagnostic systems). Put all those hives into a dis-used aircraft hangar (for a consistent outer 'climate') for extra control.....

Regards, RAB

Regards, RAB

 

[Firegazer]

I worked it out as about 15 watts before (see this thread when we last chewed it over: http://www.beekeepingforum.co.uk/showthread.php?t=2545)

That implies a big battery and reasonable solar panel could cope fairly well, if a small 10 watt heater was used overnight/when it got really cold.

The problem, I think, is that until you get to proper 'Finman cold' of -10, -20 and worse, it can actual INCREASE the energy usage of the cluster to warm them up; they (apparently) get more active and have a bigger cluster. So we want to help them keep at around 5 oC, which is where the insulation comes in, as you say. More insulation means they can maintain that optimum dormant temperature with minimum energy expenditure.

If this is all correct, it could be a problem for my bees - a quarter-sized colony with small stores and a slab of candy - because the weather has been too warm (!?) This morning it was 3 oC outside their hive so they are properly dormant, but this is probably the first time this Autumn/Winter that it has happened so they might have used far more stores than the average year quoted in the 'rule book' . . .

FG

 

[Finman]

.
Funny thing is that biggest hives get best advantage from bottom heating in spring. The queen comes down to lay and the radius of brood area will be bigger. Nucs get advantage when you give frames of emerging bees. A brood frame gives 2-3 frames nurser bees.

 

[Brosville]

Let's do some sums - if we assume 15 watts for 24 hours at 12 volts, that's 30 amp/hrs/day - classically you never design to take more than 10% of a battery's capacity per day, so you'll need 300 amp/hrs of battery - the most economical battery is probably the most expensive, so reckon around £600 minimum for the battery, then you need to generate 30 amp/hrs per day, especially in midwinter, so as a pv panel will give circa it's "rated wattage" in the UK in the depths of winter, you'd need something like a 400 w array - @£4 per watt, circa £1600, so with controllers, cabling, heating elements, somewhere about £2,500 per hive!
People grosssly overestimate the power available from pvs, and hopelessly underestimate the battery capacity needed - hence my original "forget it" suggestion............
At which point someone will leap out of the shrubbery claiming it can all be done for a fraction of the price - many have tried, but harsh experience (and a pile of stone-dead batteries) rapidly proves them wrong!

 

[Finman]

.
Heating against winter cold make no sence.
it works best when new nurser bees have emerged and bees get pollen from outside.
I use heating when temp is under +15 c and only for brood rearing.

 

[Firegazer]

Brosville,
I think your figures might be a little pessimistic, but your conclusion still holds.

When I looked at it I thought if the cluster was burning 15w, then an addition of 2 - 5 watts from a heater would make a useful difference. I also planned on only switching it on when the temperature fell below 'really cold' so working for, say, 40% of the 24 hrs. Deep cycle batteries can regularly get down to 50% without dieing, but seem to cost twice as much

All told, it was doable for a single hive that needed special help, but not lots of hives. The realisation that it wouldn't actually help reduce stores usage stopped me trying to prototype it, and I went for a big external box over the hive to provide protection from the wind and rain instead.

Finman is clearly using heating to 'shape' the environment of the colony for better expansion in Spring and (I guess) honey production. I was just worried about a small colony lasting the winter.

 

[Brosville]

I've worked in the renewable energy field for some years, and simply used "industry standard" design figures - some would say that to be entirely safe, it would be wise to double everything in size from the figures I used.

"Deep cycle batteries can regularly get down to 50% without dieing, but seem to cost twice as much

Like everything in renewables, it's incredibly complicated, but there are loads of different batteries called deep-cycle, many of them are nothing of the sort (there's at least one major manufacturer making outlandish claims)
Here's some food for thought - if you buy a "caravan deep cycle" battery, the performance will roughly be "200 cycles to 50% DOD" (dod= depth of discharge), which translates as "if you take 50% of it's charge every day, on average it'll last 200 cycles" (7 months) - it's also fairly "pro rata", so if you only use 10% of it's capacity per day, it'll last 5 times as long - 1,000 cycles, or nearly 3 years (which at £80-90 for a 100 amp/hr battery is not a cheap hobby)
For a pukka "last for 25 years" system the prices are frightening - well into the thousands for even a relatively small system

 

[Firegazer]

[getting a bit off-topic now, but probably still interesting!]

Brosville,
that's disappointing - I was hoping to try and set up something 'micro-generation' here soon, not to heat the beehive, but just to dip a toe in the water in case power prices go mad. We're also 18 houses stuck at the end of one leccky cable that goes a mile or so up the hill, so any self-sufficiency stuff could be useful if a tree comes down or something.

PV is a special pain where I am - the north side of a big hill; October to February we don't get direct sunlight at all! Wind power might be helpful, but the garden is visible for quite a way and in a conservation wotnot so anything with any efficiency is probably ruled out.

We do have a spring/well at the highest end of the garden (where the bees are), maybe 10 - 15m above the bottom garden. Do you have any experience with micro turbine, water in a pipe, sort of systems?

FG

 

[oliver90owner]

Water power. Energy available is mgh where m = mass, g= gavitational field strength and h = height of fall in metres. Result will be in Joules. One joule per second = one Watt of power. Assume about ten percent efficiency and work from there. Any improvement on the efficiency is a bonus, but would be improved as the resource size increases and energy coversions are optimised. The single most important advantage of water power is that it can be 24/7 (as long as not so small that freezing issues prevail).

Regards, RAB

 

[Brosville]

Yes! Again it's all down to "what's the resource?", and doing lots of sums - what you need to work out the potential of hydro is the flow (litres/gallonsminute), and the "drop", and go from there - classically, if you have got a viable water supply, hydro is relatively cheap to install compared to other renewables, and supplies power 24/7.
There is legislation under way which is supposed to make installation of small wind turbines a lot easier, but unfortunately it is based on a lot of rubbish data, and is aimed at roof-mounted chocolate teapots (which DON'T work because of turbulence problems) - IF you have the right resource a tower-mounted turbine can work well, and pay back fast (but if you're on a northern slope, don't hold your breath - most prevailing wind is south westerly in the UK)

 

[jezd]

Great replies from all, very useful, as was said its the insulation first with good ventilation (ie let damp out), I could then put in a 50m extension cable

 

[oliver90owner]

A safety transformer would probably be enough energy for one hive without any load, I would think. Split-mode system might not. Think safety. Think low voltage.

Firegazer,

a quarter-sized colony with small store

I hope you have reduced the effective size of your hive. Any 'vain' space to be heated, particularly across the top, is even more difficult for a small colony.

Regards, RAB

 

[Brosville]

Setting renewables aside for a second, I'd recommend a swift Google for "nestduftwarmebindung" which is very interesting about keeping bees warm in winter..........

 

[hedgerow pete]

jezd, can i ask why you are interested in hive heating, whats your reasons behind the question and where are you planning to go with the answers,

i do use heating in the bee shed but not till february and then its only to start the breeding cycle off, i have a lot of nucs set up in a field at the moment each nuc is in a 1/2" ply box as per the videos, to insulate each box has a piece of plastic foam inside the lid roof and I have just finished wrapping each hive with its winter jacket made from this stuff its like tin foil and bubble wrap it supossed to be used inside your loft but is just as good out side on bee hives.

Another beek i know has been collecting normal white polystyrene boxes from the local meat and fish market each box is cut to size and fits over the top of his nucs and the other beek i know has just done the dump a few layers of used bubble wrap from work and cover with carpet and string jobbie. all of which help but as for the heating, does bring me back to why?

 

[Frisbee]

I think.........and this is only me of course, that seeing Finmams famous picture of the hive in snow with the heating cables showing, but no explanation at the time of the fact that it is used in early spring to help a colony along rather than all through the winter is possibly a reason for why asking.........Jezd will now come along and say not so. I know when I first saw the pics I thought heating through the winter. Completely impractical for me so it never stayed in my mind, but anyone who is a relative beginner and close to an electrical supply might well have thought it was a way forward.

Frisbee

 

[jezd]

lol, 'not so!', I was just looking at the options, I knew Finman did have these heating cables from previous threads in the year but have not seen the setup in detail, or if they had been used all Winter - I suppose I was think longer term but it seems that maybe not the best approach.

 

[hedgerow pete]

the big worry with nest heating is getting them to warm and as such they dont herbinate they start to lay eggs and the nest increases, big issue there is they will try to do toilet flights and freeze out on the wing so depleting the nest, and run out of food.
i dont heat my lot at all unless the inside shed temp gets below mius 5C in which case i light a night light candle yep just one and stick it on the floor between the hives this takes the chill off and last year i tried to get a steal on the spring by waking the ladies in mid february in stead of april, i did this by bringing the shed temp up to 10 C from 7C/5C this started the queen into laying eggs, I then fed with pollen subsitue and syrup feed from then on untill the outside weather was good enough for them to forage them selves.

so instead of super complex heating systems and car batteries and all sorts of of ideas, just build a shed and buy a candle, works for me

 

[oliver90owner]

worry with nest heating is getting them too warm

There must be an optimum temperature for the cluster where basic metabolism equates to heat losses from the hive. About 8 degrees, or a tad more, is the minimum temp of the cluster surface so ambient, with that cluster temperature, is the required target for the air entering the hive, no more and not too much less - when the cluster is at it's tightest.

That being, if the external heat energy source is more cost-efficient than the internal chemical energy store at 50p per kg! Hive heat loss will be directly proportional to the temperature difference given there is reasonable air movement (Newton's Law of cooling). No brood situation might be down to twenties celsius at the centre of the tight cluster but must rise to middle thirties when brooding commences. And/or there may be slackening/tightening of the cluster to regulate the core brooding temperature if brooding starts with a vengeance and the ambient changes by a few degrees. I reckon it is such that it would need some fairly complex algorithms to be sorted for a microprocessor to be able to compute the requirements for an individual colony. For us - definitely leave most of it to the bees! It is so simple for them, too cold and cannot cluster tighter - eat more. Stores used up (or unreachable) - die. Nothing else they can do about it.

Regards, RAB