Living offgrid with small solar system(s)

[George Harmony]

Im wondering if members here are living offgrid with solar power, so we can share experiences and tips.

After my roof was installed and i have water in my toilet and seperate bathroom i mooved in although the house was and still not finished yet.

Ive installed some dc 12volt lights with first a 20wp panel and only 7ah deel cycle battery. It works great.

Now i have only total of 80wp panels and im able to add more lights, pumping from a well with a dc pump tp my watertower-tank and charging a rechargeable fan, laptop and hp's.

All of this with only 3 x 7ah batteries. Already 6-7 months and still working well.

Must perhaps add one more panel for my planned (peltier) fridge or a normal fridge with low power consumption.

I will be happy to hear your solar experiences (off grid)

Thanks.

[50baht]

http://www.taspower.com/

[George Harmony]

@50baht,

Thanks for the link. There are several pv solar panels and related products suppliers in Thailand.

Im more interested in experiences and tips from others, for example if they have experience with stepup down modules to gain more and constant charge or working with super capacitors to start e.q. a fridge etc..etc..

[George Harmony]

This a a handy coffeemaker,especially when you have surplus during the day of the incoming power.

Anyone knows whether i can buy this in thailand??

Edited February 21, 2016 by George Harmony

[beedee]

Maybe aliexpress?

http://www.aliexpress.com/item/Free-shipping-fee-12V-car-special-fashion-casual-coffee-tea-car-coffee-maker-electric-kettle-car/1967792037.html

http://www.aliexpress.com/item/free-shipping-12V-Auto-hot-water-boilder-car-Coffee-Tea-Hot-Soup-Maker-Car-Kettle-12V/32241343850.html

http://www.aliexpress.com/item/car-Coffee-Tea-Hot-Soup-Maker-Car-Kettle-12V-Volt-4-Cups-Hot-Water-Boiler-auto/2039116505.html

[Jing Joe]

Are you using a brush-less water pump, hope so? Brushes wear out surprisingly quick just when you don't want that.

Chinese brand Topsflo via Alibaba have really nice brush-less magnetically coupled low Voltage DC pumps.

E.g. TL-C12H-12 1508 15l/min max, 3 amps, 8 metre head. Many models, many water pipe connections

Only about 750 baht, fist size and perform beautifully. There is an 11 metre head pump but is 24v. How high is your header tank to the very top versus how deep is the well?

They have submersible versions with a slightly different code but the leads might be only 300mm long. Needs a bit of extra attention to waterproofing leads.

They have P.V. pump models that are Solar panel friendly (so the pump is exclusively connected) so one panel, without a battery, will accept the morning sun with not enough volts to pump, yet work well all day in better sun and accept the afternoon low volts scenario.

A bilge float switch turned upside down mounted at the top of the tank works well to prevent overflowing your header tank and nice to see it all start up about an hour after sunrise. A switch to bypass this is good for testing and an off switch is sensible too.

You are using LED lamps of course?

Peltier fridges are only about 40-50% efficient. You could set up a warm water reserve tank by extracting the waste heat from the hot side of the peltier thermo couple device. Lot of work though.

Do you have solar hot water?

How about many metres (say 50-75 ?) of 1/2 inch black poly pipe neatly coiled on the roof and a suitable solar panel for the above pump?

It will only pump when the sun is shining. Not the perfect solution but a good start.

Ideally you need to make a 12v controller that only pumps when the temp of the pipes is hotter then the temp in the top of the storage tank.

A storage tank can be below the roof level but needs a non-return valve for night so you don't warm the roof then.

If lucky enough to mount the storage tank at least a metre above the solar collecting pipes, you wont need the non return valve.

You will very likely need a small vapour release valve at the top most point in the system. Very nice, very small.

12 volt compressor fridges are much more efficient but you sure would surely need more that 3 x 7 A/H battery bank even for a larger portable type ESKY camping size.

They would use about 5 amps when running and that's 60 watts.

Small jug water heaters are better replaced with small gas stove. 150 watts is high and be very wary about plugging into car cig socket. The wiring is not much better than 10 amps (that's what the sockets are usually rated.) My cars wiring was burnt from someone before me. 150 watts is 12.5 amps at 12volts neat at night time.

Warnings are out there for the small camper stove that over heat the gas canister and explode.

Most prone when/with large diameter pots and especially with the canister cover opened.

Considering wind too? Don't believe many promotions saying their brand is quiet, until you do lots of internet research and luckily visit one.

Beware; many Chinese made w/g manufacturers flood the internet with their own promotion web sites.

You may be a bit close to neighbours anyway for even the quietest model re noise and you need to get it up well above trees and roofs.

Have you had many long stretches of cloudy days?

Look out for solar panels that have more cells than usual, and their open circuit voltage is rated higher.

They perform better on dull days.

[gregk0543]

I want to setup something like yours in Myanmar. Hard her to find a DC pump.

Can you give me some details on what you used, where you obtained it and how much it cost. Thankyou for any help in this.

"Now i have only total of 80wp panels and im able to add more lights, pumping from a well with a dc pump tp my watertower-tank and charging a rechargeable fan, laptop and hp's. "

[Paul944]

The problem with 12 volt lights and cookers is the amount of current they need. This requires thick copper cables and increases the change on fire. Also fridges, freezers, airco units and other appliances that support 12 volt are difficult to find and expensive.

do you consider a real off grid installation with an inverter or just a 12 volt installation with a few batteries to cover the night?

A real off grid solution will cost much more as just paying the electricity bill the coming 30 years.

[steven100]

The correct way for complete off-grid as Paul mentioned ... Panels + batteries + inverter .... for a house you need 5KW

I believe there was another thread on this about a year or more ago ... just search solar on TV ...

A proper set up can cost 150k - 200k ... but that will keep you going for 10+ years & no more power bills.

[Autonuaq]

The correct way for complete off-grid as Paul mentioned ... Panels + batteries + inverter .... for a house you need 5KW

I believe there was another thread on this about a year or more ago ... just search solar on TV ...

A proper set up can cost 150k - 200k ... but that will keep you going for 10+ years & no more power bills.

the trick and the problem is the invert and the deep charging batteries.

as well the cleaning of the panels.

the captivity is deepening on what you want and need.

you can cool a house with 500 W if use the right materials and can light with 50 W if you choose the right way of doing it.

water pump if needed ball bearing you can built your own water purification system easy

TV if needed you can use digital, internet if needed you can use you smartphone as a wifi. there are smartphone that load on solar as well power bank

and if you have street light you even can generate from streetlight power for you with the correct panel to convert the l;ight

then if you live near power line you can get light for free due to the magnetic field

hot water you can get for free on solar heater

and food depressing on the area you live you also can get most of it for free if you know where to look (not stealing) mother nature can help you on that too.

many many option to live of the grid.

the essital is the choice you want to make and how to do.

good tools and equipment make it possible and do it long

about every 10 years to replace the batteries and probably the inverter.

Edited February 22, 2016 by Autonuaq

[Jing Joe]

Are you using a brush-less water pump, hope so? Brushes wear out surprisingly quick just when you don't want that.

Chinese brand Topsflo via Alibaba have really nice brush-less magnetically coupled low Voltage DC pumps.

E.g. TL-C12H-12 1508 15l/min max, 3 amps, 8 metre head. Many models, many water pipe connections

Only about 750 baht, fist size and perform beautifully. There is an 11 metre head pump, but is 24v. How high is your header tank to the very top versus how deep is the well?

They have submersible versions with a slightly different code but the leads might be only 300mm long. Needs a bit of extra attention to waterproofing leads.

They have P.V. pump models that are Solar panel friendly (so the pump is exclusively connected) so one panel, without a battery, will accept the morning sun with not enough volts to pump, yet work beautifully well all day in the better sun and happily accept the afternoon too low volts scenario.

A bilge float switch turned upside down mounted at the top of the tank works well to prevent overflowing your header tank and nice to see it all start up about an hour after sunrise. A switch to bypass this is good for testing and an off switch is sensible too.

LIGHTS; You are using LED lamps of course?

Peltier fridges are only about 40-50% efficient. You could incorporate a warm water reserve tank by extracting the waste heat from the hot side of the peltier thermo electric device. Lot of work though.

Do you have solar hot water?

How about many metres (say 50-75 ?) of 1/2 inch UV stable black poly pipe neatly coiled on the roof and a suitable solar panel for the above pump? Position the pump at the colder inlet to the pipe collector. Check temp specs too. There are hot water models.

It will only pump when the sun is shining. Not the perfect solution but a good start.

Ideally you need to make a 12v controller that only pumps when the temp of the pipes is hotter then the temp in the top of the storage tank.

A storage tank below the collector needs a low-forward-pressure type Non-Return Valve for night so you don't warm the roof then. A 12v NRV on the same panel might use more power than you would like. Dismantle, replace with lower pressure spring and rewind with more turns, lower current.

If lucky enough to mount the storage tank at least a metre above the solar collecting pipes, you wont need the non return valve.

Either case you will very likely need a small vapour release valve at the top most point in the system. Very nice, very small and available.

FRIDGES. Always a big subject. 12 volt compressor fridges are much more efficient but wouldn't you need more that 3 x 7 A/H battery bank even for a larger portable type ESKY camping size.

Lead acid car/bike batteries are not all that good at cycling but probably cheap enough there.

They would use about 5 amps when running and that's 60 watts. Use your digital thermometer during the day to check cold loss to the outside.

If you added extra outboard foam insulation on the lower box alone, you might cut down the duty cycle and use less average power most needed in the dark hours.

Small jug water heaters are better replaced with small gas stove. 150 watts is high and BTW be very wary about plugging into car cig socket. The wiring is not much better than 10 amps (that's what the sockets are usually rated.) My car wiring was burnt from someone before me. 150 watts is 12.5 amps at 12volts neat at night time and they are a bit slow naturally.

GAS STOVES. Warnings are out there for the small camper stove that over heat the gas canister and explode.

Most prone when/with large diameter pots and especially with the canister cover opened.

SOLAR PANELS. If you are lucky enough to mount panels on brackets, pay attention to adjustment angles. You could find the higher angle adjustment you leave in place all year flavoring the "winter" sun, might cause you grief with the summer sun only striking the back of the panels from sun-up till 9am? and from 3pm to sunset.

Angle versus output mostly does matter (try it with your amp meter across the output on a spare panel.) Dusty glass quite inhibits output. Watch the before and after mopping.

Are you using a regulator?

Check out for solar panels that have more cells than usual, their open circuit voltage is rated higher.

They perform better on dull days. Can connect in parallel with existing panels that should already have isolating diodes in them. An ammeter monitoring both kinds of panels is nice to watch the difference and even in light rain they can produce.

Considering wind too? Don't believe many promotions saying their brand is quiet, until you do lots of internet research and luckily visit one.

Beware; many Chinese made w/g manufacturers flood the internet with their own promotion web sites.

You may be a bit close to neighbours anyway for even the quietest model re noise and you need to get it up well above trees and roofs.

Have you had many long stretches of cloudy days?

Good luck. hope this bit helps. keep us across it all.

[George Harmony]

Up till now my current system works well and im satiafied.

About fridges. For fruits and vegetables ive made a fridge with no power. Only for drinks and meat im currently orientating for 12volt fridges. If i have to add more panels and more battery capacity i ofcourse will do.

I admit that 80wp system is very small and to be on the save side i will add more. But im convinced that standard size non AC houses with 2 bedrooms can be offgrid with a system max. 250wp and battery capacity of 200ah.

For warm water is indeed not so difficult to make solarheaters and store it in an insulated tank.

Will post some picts soon.

For those who sont have exp with solar here an informative video. Imagine you have 5x more capacity........

https://m.youtube.com/watch?v=-JWC8Vspa-s

Edited February 22, 2016 by George Harmony

[Psychic]

Speaking of fridges, I've read an article on the internet, not sure if I've got it downloaded somewhere.

Basically the proposition was fridges are built all wrong as cold air sinks and it is released in a normal fridge when you open the door.

The guy put extra insulation in an old freezer, wired it up so that when a thermostat got above 2-3C the power went on and made some easy access shelving.

Apparently the power consumption was a fraction of a normal fridge.

[Crossy]

Yes ^^^, a chest fridge won't lose so much chill when the lid is opened.

The 'esky' style cool box is actually pretty efficient

[Jing Joe]

If you are doing it on the cheap in a small system George, you can do just about anything on 12 volts.

So stick with it since you seem already very satisfied. Been there, done that, way back a with DC bank.

If its not a high current appliance on your 12 volt system, standard 240v switches are OK and more reliable than some of the smaller L.V. switches.

So you may choose to leave inverters alone.

Transformer inputs on some 240v appliances don't usually like AC with high harmonic (SQ Wave) component from inverters nor do some switch mode power supplies eg. battery charging power supplies.

Many Inverters produce Radio Frequency Interference RFI and they are mostly square wave even though they SAY they are modified Sq wave.

Will cost you more for a pure sine wave.

Few are comfortably efficient unless fully loaded and unless you have one that auto-switches on, on demand, including when intermittently loaded (like a fridge in the night) you will have to leave it running all the time.

Digital TVs suffer a bit from RFI.

LED lights are fantastic with your 12 volts. You don't need the expensive fancy decor models. 10 watt 12v LED modules are everywhere and so cheap and bright.

You can carefully convert what standard lamps you can easily get your hands on.

Deep cycle batteries will cost more but should last 10+ years as mine have done and as someone has posted. At least you have started.

Supercaps need specific charging conditions that you may not want to get involved with.

Rechargeable devices often come with the cigarette lighter plug and there are multi outlet x 4 socket devices and USB charging sockets.

Shop around you may already be pleasantly surprised.

Edited February 22, 2016 by Jing Joe

[ggt]

This is a great thread...lots of helpful information from folks who have their focus in the right direction...

Kudos to those who dabble in alternative power systems...

Good investment...but I continually worry about the life of the batteries making it a bit more expensive than anticipated...

[George Harmony]

About batteries. If you connect all loads well and use a good charge controller it will protect your battery.

For long life of the batteries its wise not to drain your battery empty but only 50%.

Indeed deep cycle batteries are relatively expensive. Thats why i try first with small 7ah batteries. Also when during the day the batteries are fully charged you in fact have a surplus and thus free electricity. In other words, using my dc pump, charging laptop and hp's and even watching tv during the day is completely free without draining the batteries.

[George Harmony]

About my simple water system.

As i said before i mooved in to my unfinished house with only 20wp solar system. A sanyo well pump was installed and i used a small genset.

Then i tested a small circulation pump 12volt. With a footvalve im able to pump water from a 6m well to my watertank 3.30m high. Amazing. Ok, its only a 2.1amp pump and only 2-3 liter per minute. Im not using a lot of water. Average 150ltr per day.

Since this pump is only 2.1amp i can run it with my 80wp solar panels and also charge my batteries. Handy is also that this pump have a pressure switch, so automaticly turns off if my water tank is full. I only use the pump during watt peak hours to fill the tank.

No need electricity for the flow to the cranes due to gravity.

Edited February 22, 2016 by George Harmony

[Muhendis]

On the subject of deep cycle batteries. You need to be aware that there are three options readily available.

• The first and by far the cheapest is the flooded lead acid battery (FLA). These are available and made in Thailand for 6,800 Baht for deep cycle 200 Ahr battery. They will need maintenance and a well ventilated room. The maintenance required includes regular topping up with distilled water and an occasional desulfation cycle.
• Next comes the maintenance free, sealed lead acid battery. As the name suggests you won't need to worry about topping up and although they will become sulphated it will not be serious enough to worry about and in any case desulfation is risky on these unvented batteries. These are twice the price of the flooded lead acid batteries.
• The third and last is the Lithium iron phosphate battery (LiFePO4). These are a lot more expensive (at least 5 times) than lead acid but they are much more solar friendly and you won't need so many for the same total capacity.

The problem with solar power is the inconsistency of solar energy. It is this which is the main cause of sulfation in lead acid batteries and can reduce their capacity and shorten their life if not dealt with. Lead acid batteries need to be fully charged to 100% every cycle to get the best life expectancy from them. The anticipated number of cycles from deep cycle lead acid batteries is dependent on the level of discharge. If, for example, the batteries are subjected to 80% discharge and then fully charged again then they will be good for something like 500 cycles. On the other hand LiFePO4 batteries will be good for 2000 cycles and they are good for partial charging without suffering any detrimental effects. FLA batteries will take a fair amount of abuse but their maintenance free pals are more particular and will not tolerate overcharging. LiFePO4 batteries need additional electronics to manage them to ensure all cells are monitored for such things as balancing and over/under voltage.

I have a large system which uses FLA batteries at the moment and for me, well, lets just say I have more interesting things to do than run a monthly desulfation cycle and, even with a single point watering system I don't need the hassle of going into town for some bottles of distilled water. When time is due for a battery change I will switch to LiFePO4's. My inverter/charging system is programmable so I can easily accommodate the small changes required for the FLA to LiFePO4 swap.

Hope this helps

[Stuart21]

About my simple water system.

As i said before i mooved in to my unfinished house with only 20wp solar system. A sanyo well pump was installed and i used a small genset.

Then i tested a small circulation pump 12volt. With a footvalve im able to pump water from a 6m well to my watertank 3.30m high. Amazing. Ok, its only a 2.1amp pump and only 2-3 liter per minute. Im not using a lot of water. Average 150ltr per day.

Since this pump is only 2.1amp i can run it with my 80wp solar panels and also charge my batteries. Handy is also that this pump have a pressure switch, so automaticly turns off if my water tank is full. I only use the pump during watt peak hours to fill the tank.

No need electricity for the flow to the cranes due to gravity.

Interesting thread, George.

Only suggestion I could make would be to add a spare pump in parallel to the existing one with a valve & a switch - then when your current pump (eventually?) 'buys the farm' you will have water again very soon.

Or, just have a spare pump ready -

Edited February 22, 2016 by Stuart21

[George Harmony]

Interesting reactions about batteries and tips about spare pump. Thanks.

About my lighting and Tv use in my current situation:

A 3watt led tube is enough in my living room plus 2 table lamps each 1watt led bulb, average use about 7 hours.

Toilet,seperate bathroom, bedroom and kitchen each 3watt ledtube on an average day max. 2 hours total.

ProjectorTV which use 16watts on an average day 3 hours.

Total lets say 100 watt hours per evening that draws from my 3 x 7ah batteries which in theory can give 252 watt hours.

One have to adjust bad habits if livig off grid with small systems like turning tv on and not looking, burning lamps in spaces where nobody is there etc etc....

Once more, during the day (watt peak hours) i can watch tv as long as i want and watch missed favorite programs also on youtube WITHOUT draining my batteries...totally free ... And my batteries will also be fully charged.

Imagine i have 3x more solar capacity and 10x more battery capacity .....

Edited February 22, 2016 by George Harmony

[George Harmony]

A pict of my unfinished living room with only 2 table lamps burning.

[chipstack]

Stateside I had a large class A (bus RV). It had an almost full size frige amd freezer that ran on propane (essentially a pilot light) and a little battery power. Likely an efficient home off grid solution.

[AlQaholic]

Panels is the wrong way to go ATM, they are a bit unreliable, and performance deteriorates in warm climates. I am looking for a way to heat up water to boiling temperature and use the energy from that to produce electricity.

[George Harmony]

Charge controller:

For my small system i use this chargecontroller which is in thailand available at amorn. Rather handy cause of the different kind of outputs and buildi voltmeter and also a fuse already buildin.

A chargecontroller cut the charge when the battery is full. Also cut the load when you drain your battery till a critical point.

Since this is not an mptt controller i connect a stepup-down module between my panel and the chargecontroller enabling constant/stable charging even when input voltage drops below 12volt.

Yesterday i slept at around 1 midnight and took a pict of my chargecontroller. Battery voltage status more than acceptable

[Jing Joe]

The problem with 12 volt lights and cookers is the amount of current they need. This requires thick copper cables and increases the change on fire. Also fridges, freezers, airco units and other appliances that support 12 volt are difficult to find and expensive.

do you consider a real off grid installation with an inverter or just a 12 volt installation with a few batteries to cover the night?

A real off grid solution will cost much more as just paying the electricity bill the coming 30 years.

Overall one cannot compare George's basic 12v system (that he can ingeniously get around many of the home needs), with a full blown off-grid panel, battery and inverter system. Chalk and Cheese.

Some of what Paul said above is relevant but;-

LIGHTS;

Just two 6 watt LED lights consume only one amp total and they give lots of light.Practically consider the actual bare wire size in extension leads rated at ten amps.

That's just a rough idea that 12v "lights" as mentioned by Paul above are not what they used to be and don't need the heavier wiring as in the past.

Sure you MUST do the sums of both the current needed in the wiring and the run lengths involved. Measuring any 12 v voltage drop is so practical and safe to research.

COOKING: Cooking with 12 volts? Surely NEVER. (Even with some full blown off-grid systems) Gas is the only way.

FRIDGES; As others have mentioned, you can get bye with the ESKY type where you lift the lid that have a 12v compressor for small 12v systems, and can be improved with extra foam on the lower box. Vertical 12v caravan fridges lose cold air when they are opened. You could use a three-way caravan fridge;-. 12 V, Gas and 240v with the emergency generator described below. Do your 12V sums;- duty cycle Vs current and then total A/H over night.

OTHER; Air conditioning with 12v is also almost out of the question, but fans might suffice and are low power. Is it too humid to contemplate a small evap. unit?

BATTERIES ; Sure George may be trialing SLA 7 AH batteries just now, and since he is gaining confidence with the project, he might seriously think of replacing/expanding with Deep Cycle instead. Research any compatibility issues.

SECURITY LIGHTS; Certain 240v models I convert to 12v, controlling a 12v 20w LED work flood light. Examine & draw Cct.of Pwr. board. Feed 12v to bridge rectifier. There's a 24v Zener relay supply & 5v Zener supply for sensor board. Swap 24v relay with common 12v relay. Relay contact needs some 12v for LED. Good luck.

WIND POWER. A great field worth careful research/contemplating (especially low noise factor). Think;- Solar;- max sunlight hours limited if fine. Wind;- 24hrs potential if windy. The co-incidence of no sun and no wind is low and even then a cheap, small , very quiet 700 W two stroke generator with a decent 12v battery charger (as much as 30 to 50A if you can get one) is a comforting standby. A cheap 10 to 15 A charger would get you bye.

Warning, such simple generators during load changes such as fridge cycling on/off give off surge spikes that kill some electronic 240v power supplies you might be tempted to also use during the emergency. Certain battery chargers could be vulnerable too?

George seems rightly happy with his venture and good on him.

If he puts permanent light wiring in the house he could think ahead for a future buyer who might want the grid, or for himself to have a full blown off-grid system later.

The more distribution circuits (even with their standard wiring) the better, because of less current each circuit, and again; LED lights are so current-economical.

However; the separate dedicated "power" circuits (term used advisedly) should not have standard 240v sockets in the mean time because any 12v "appliance" plugged in to them must not be capable of fatally plugging in at another standard 240v home.

N.B. Cigarette lighter sockets are not usually high quality or reliable perhaps even with just 5 amps with a fridge. There's a much better similar design available that caravanners use.

Generally; If thinner wires are chosen one has to consider the DC circuit breaker or fuse sizes back at the batteries to break in the event of a short circuit at the end of the run.

Inappropriate comparative values could see the wire instead acting like a fuse and therefore burn. So suitable wire and fuses must be factored in.

Suitable fuses in the appliance or the socket are a safeguard if the appliance goes short circuit, but a S/C en route needs the suitable all important battery-end fuse.

If the battery bank is not far from a "power console" facility and fridge etc., much heavier wire could be conveniently used.

But I could be wrong in some of my help to George. It only comes from my 38 years of living off grid.

[George Harmony]

About fridges.

Ive been told that gasfridges absobs a lot of gas.

It would be a challenge to make my own fridge.

More info 1st pict: https://m.youtube.com/watch?v=u2C9XbAVz5U

Anyone have exp with peltier fridges? They coo down 20-22c below ambient temp. Does this mean that i can make ice if my room temp is 20c????

If i can make ice its not so difficult to make a cooler box based on pict 2

[George Harmony]

@jingjoe

You r 200% right...... (y)

[Jing Joe]

About fridges.

Ive been told that gasfridges absobs a lot of gas.

It would be a challenge to make my own fridge.

More info 1st pict: https://m.youtube.com/watch?v=u2C9XbAVz5U

Anyone have exp with peltier fridges? They coo down 20-22c below ambient temp. Does this mean that i can make ice if my room temp is 20c????

If i can make ice its not so difficult to make a cooler box based on pict 2

Yes, gas fridges are energy in-efficient. Compressor have a C.O.P. coefficient of performance of about 2.4.

that is 2.4 times the transfer of energy comparable with straight resistive heating for example because of the evaporative nature of the beast.

Yes peltier (thermo electric) fridges will drop 20 -22 below ambient BUT you can stack two elements and get more like 40 below ambient.

They do this in Science labs.

There are different size wattage devices. Best start with two new ones of same model.

Don't skimp on getting the heat away from the hot side of the assembly.

Likewise have large enough cold surface and even a fan inside too.

Make a larger hot surface with 1/8 inch (at least) aluminium plate 500 x 500 ? and rivet many 10mm x10mm aluminium U channel heat sink type fins.

Zinc heat sink paste helps.

But even then peltier are only about 50% efficient.

[Muhendis]

Panels is the wrong way to go ATM, they are a bit unreliable, and performance deteriorates in warm climates. I am looking for a way to heat up water to boiling temperature and use the energy from that to produce electricity.

You are right about loss of efficiency at elevated temperatures but this should be taken into account at the design stage. Reliability is not a problem if you get them from a good source and they will last 25 years at the end of which time they will still give 80% of their original output. Solar panels are a mature technology which is favoured by most.

If you want to produce electricity from solar heated water there are many people who have successfully used large satellite dishes to focus the suns energy onto a water container which will produce boiling water. Another option could be the Stirling Engine information on which is here https://en.wikipedia.org/wiki/Solar-powered_Stirling_engine