Small Scale Hydroelectric

David Trammel's picture

Back in the early 80s, I ran across a book from the 40s which detailed how to use a car generator (not alternator) and a few 55 gallon drums to build a small hydroelectric generator. You would pair this to a small earthen or rock dam, built across a farm creek or small stream.

Saw that a company is building a modular system to do small hydro, though their webpage seems geared towards small industrial or city size units. Lowest setting on their slider pricing does $9K in electrical generation. Way bigger than most single residents would need. Still the idea of setting up a renewable energy source that doesn't kick off due to lack of sunlight or wind would be useful.

Since that earlier book I've seen small floating water turbines you could place in a stream. You could daisy chain several of them for more power. This looks more interesting for small scale:

mountainmoma's picture

You do not need 9k, it is not hard to do. But, I would not want one floating in a stream, too much breakage and upkeep. You just make a small inlet box in the stream with screening to no get critters and plant matter in, and small diameter PVC pipe comes off of that to where you put the micro-hydro, then PVC or other piping to go back into the water source. A charge controller to the batteries at the other end, etc....

certainlly, it is the most cost effective way to have some electricity. Alot of us do not have year round running water, I know it doesnt take much, but it does take some.

David Trammel's picture

A storm with high winds knocked out power across St Louis this week, is small localized spots. I lost power for about 12 hours Wednesday. LOL, with all the prep I did for Covid in February I found that I was woefully short on my battery lighting. Not to mention I'd not kept my laptop charged. And the cell phone was at a mere one bar of power. I need to fix that soon.

That said, Thursday is one of the two evening I go in to clean at the animal shelter I volunteer at. There is another, a woman in her early 20s who is on the shift as well. we get into some pretty interesting conversations given the age and gender difference. We got into a discussion on emergency power given the outages.

I don't have sunlight, nor wind enough for either option there. I told her I'm leaning towards setting up a battery backup rather than a generator or short term energy. The plus side is its not noisy like a generator and so your neighbors won't know you are a prepper, as long as you don't use the power for too many lights. Down side is its probably more costly. Yeah she mentioned a neighbor of hers with a generator and how loud it was.

I imagine you have more options given the rural nature of your home MM.

mountainmoma's picture

I like battery banks, I have a bit, and yes, it would work just as good in an outage no matter if it were charged from the grid or solar.

Another option, or an additional one, is to have a larger inverter that you can use from you car for back up power.

I think it is good to have multiple options.

I have had a battery bank "break" right when I needed it for an outage once ! Alright, it was likely already past its prime and I just hadnt noticed yet. But, at that time we had a critical need for it for heat, and it was cold. so changes were made once we were past that storm.

Anyway, city with shade like you or me with some sun, the options and strategy is very common I think.

Cant you charge your cell phone and laptop in your car ? They do not need much power, you can use the cigerette lighter outlet for those.

I have some battery back up in the house, that usually works, but back up in case it doesnt is: the car cigerette lighter port for small charges ( small inverter that can plug in there was under $20) and a larger inverter that connects straight to the car battery with a thick extension cord, properly sized to use with it, this can power something larger like a refrigerator ( under $100 for both, I think $80ish) .

The other things are strategies, like alternate ways to get warm and heat food that do not need electricity, practice with those. I usually cook on my electric stove or my sun oven, but I have a dual fuel camp stove ( will run on unleaded gasoline), a propane camp stove and a butane backpack stove,( I do not find that propane canisters last well, I would not like to count on them, you go to the garage and they have vented out..... ), a rocket stove that can quickly heat up a large pot of food burning twigs off the ground, and of course the wood stove in the house.

I usually use battery backed up lights when the power is out, but I have 2 kerosene lanterns ( and the kerosene lasts forever in its container), a white gas camping lantern, and candles.

I can run my well pump off battery bank, and used to routinely, but now I also have a 2500 gallon water tank ( so now I dont usually run that off back up power), and in case that goes wrong, 4 5gallon water containers in the laundry room, and I have thought about where else there might be water. I know someone in a city block neighborhood house nearby that has a large water tank, I think as large as mine, next to his house in his side yard ! While I think he stores his roof catchment water in it, it serves the same purpose as my tank, if his city water is out, he has water.

So, I think most off all that has nothing to do with location and can be done anywhere. Redundancy too, have 3 ways to meet all critical needs.

I also agree that it is good to not stand out with preps, and if you dont flaunt it, yes, the battery back up is less noticeable and so not subject to theft. It is more pleasant to not have the noise.

Sweet Tatorman's picture

Good advice from MM on the merits of redundancy. I would caution against relying on your car battery except as a last resort for several reasons. First is that they are not designed for deep discharge. The second is that if you are like most people [I include myself here] you only replace your car battery when it is totally worn out at which time you have your neighbor jump you off so you can go buy a new one. Murphy's law would suggest that when the need to use it for backup arises it will be at a time when it is on its last gasp. As I have mentioned here before, like MM I also have battery backup that I maintain charged off of grid power. I do have a bit over 2 kW nameplate of solar panels with all the necessary accessories which stay in storage and have never been deployed. If I ever had a really extended outage where the battery bank was nearing fully discharged the solar would get deployed in a ground mounted arrangement. It never has happened and likely would be a full days job. One of my redundancies is to have set up my car alternator as a charging source simply by adding a suitable connector with fusing directly at the alternator. While it will vary with the vehicle, mine will reach full alternator output of 50A at an engine RPM as low as 900, essentially a fast idle which I achieve by inserting a small shim in the throttle stop. Using a 100 hp engine to generate just a couple of hp to drive the alternator is very fuel inefficient but this is not a concern for an infrequent use. The upside is the you can generally expect to have an operational vehicle with gas in the tank. Small gasoline engines such as a portable generator that may set for years before needed have a habit of not starting when you need them. For what I understand you battery needs to be I think you are talking about 200 lbs or less of battery. That amount of battery will likely have a recommended maximum charging rate of less than the output of your car alternator. Be assured that you can charge them much harder. This would be undesirable for a daily cycling service but for charging hard rarely this should not present a problem. No charge controller would be needed.
Photo below is the connector and fuse arrangement right at the alternator of my car [1986 Toyota Camry BTW].

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Sweet Tatorman's picture

This cable with connectors gets power from auto to battery bank. I would only need about 35' vs the 100' shown but that longer length is what would be needed should the solar panels ever need to be deployed.

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mountainmoma's picture

I think that is a great idea, and it looks very simple.

mountainmoma's picture

Except for the charging of small things like your cell phone, the use of the car is not about relying on its battery, but on being able to idle it and use it as a generator. I also would never recommend discharging a car battery too much, if you use it for a long time or for a large load, you idle it. Alot of critical loads, like a refrigerator can be kept cold by idling the car for an hour twice a day, or similar, YMMV. But, also, should not be scared to go plug in the cell phone or laptop.

I do not have anything hardwired, but my inveter that clips to the battery is only used when the car is idling, so it is not draining the abttery at all

mountainmoma's picture

The first critical need is shelter, and in that I include clothing, protection from the elements. This will kill you quickly.

This is the more important area vs power backup.

Ways to keep warm if your furnace is out: Layers of clothing or blankets, of course; make a smaller shelter within your house, for example, set up your small dome backpacking tent in the living room, and put your sleeping bag in that, or build a fort with your couch cushions and kitchen table, and get in there with your blankets or sleeping bag; or just get yourself and yoru pets or other people in the smallest room you have, with all the blankets.

The storm could breach your shelter, break a window, drop a branch thru the roof. At minimum have a roll of plastic and a staple gun; second layer up is to have a tarp and small longer boards, easier with 1/2 inch or 1 inch thick than with 2x4s ! . The wind will rip off a tarp stapled or nailed to the wall or roof, but if you attach the tarp with the boards and nail thru the board it will hold ( yes, I have had to do this in the middle of a storm) It would be nice to have plywood to put over a broken window, but most of us do not have room for alot of extra plywood.

If you cannot keep the weather out, you can put all the blankets in the car and idle it with the heater on if needed. Or go to your neighbors front door. I have never had this happen, but I do keep extra blankets for the front room hide a bed, and I hope other households do the same in case it is my house with the tree thru the roof when the roads are down in the storm.

Always, always, always have more than 1/2 tank of gas in your car. Consider the 1/2 tank mark as empty and go fill up when you hit that. It could save your life -- the car has a heater and is also a generator to charge your communication devices, it has a radio for emergency information, and a light to read by. It is also water and wind proof, although not insulated at all. I could also plug my electric kettle into the small inverter and make hot water. an idling car with heat, a cup of warm tea, cuddled with the cats and blankets would be bareable. Everything is better with warm tea

David Trammel's picture

I'd taken my car in to be inspected. My sister was going to take me to the shop to pick it up when the storm hit. Rain was so hard, she had to pull over and wait for it to pass, so by the time she got to me, it was too late to go get it. The lack of car meant I couldn't go to get ice either.

Though the neighbor offered, so that wasn't a problem. And I have 6 one gallon frozen jugs in the bottom of my freezer for just this occurrence. I took the lawn chair out to the front porch, grabbed a book and some water and read until it got dark.

mountainmoma's picture

Well, that was a very short outage, 12 hours, so a good wake up call.

yeah, when multiple things are wrong at once in an emergency, it reminds you about redundancy in meeting needs all right !

Was the getting ice thinking it would be longer than 12 hours and keeping the refrigerator cool ? Not worth an accident. Freezer stocked with meat, and all other space filled too, including froozen gallon jugs with water, will keep the food from thawing if you dont open the door for 2 days, maybe , longer if it is a chest freezer, they are better insulated. The power company with our Planned Power Shut offs, where they turn the power off on purpose, will keep it off 48 hours and then leave it on for at least over night before turning it off again just so they do not need to reimburse for lost freezer food.

Yes, I know about how hard and bad the wind and rain can be -- not a time to be out driving. We get 60-100 inches of rain a year, all at once it seems, realy intense flooding windy storms, but they are in the winter. It does only rain between November and April, the worst in Jan and Feb

mountainmoma's picture

I only have the freezer part of my refrigerator, and freezing is not my main way to have food storage either with food I am counting on or money invested in food.

The food I count on is shelf stable. The freezer has 6 pounds of butter, cheese and yugurt cultures and a pound of yeast, which dont care if it thaws and refreezes; Frozen blueberries and persimmon pulp, and some veggie burgers and sausages I got for special treats --

Anyways, my thought isnt just powering the freezer it is that sometimes things break, murphies law, if it can break it will and at the worst possible time. I havent had a refrgerator go out in a storm ( yet) but I have had power surges before/after outages take out an electric stove control panel, the electronics on a washing machine, and would have fried the water heater electrics winter before last, but I had a timer in between so it just killed the timer and scorched the wires and the water heater stayed fine. ( this took place over 20 years, it doesnt happen every storm outage -- unplug or turn off breakers once you have an outage for your appliances and electronics so they wont get zapped when it comes back on)

I have now gotten rid of both my modern stove and washer in the last couple year, the washer went away yesterday. My new washer is from the 1990's, maytag, works great, no electronics. The stove is 1940's. Yes, I do know from experiece that a power surge can singe wires too, but that is easily fixable. Planning for worse upkeep on elecgtrical lines as society slowly steps down

I have heard that besides canned meats that some people make biltong, you need to look that up, but it is a very easy way to make a dried meat. I have canned chicken, which is easy, you shove pieces of raw chicken in a jar with a bit of salt and put it in the pressure canner, it makes its own juice when it cooks. You can buy canned meats of course, and canned yodders bacon even. But the freeze dried meat is very expensive.

Sweet Tatorman's picture

I have looked at small hydro on and off for about 45 years. It has always had huge appeal to me. Unfortunately it would be the rare property that would have the combination of head and flow to make it competitive with solar panels readily available at less that $1/watt. It was easier to pencil out back when panels were $5-10/watt. There is a lot to be said for no moving parts.

David Trammel's picture

I've mentioned I want to put a sizable shed in my backyard, and run power to it. I figure when I do that, I'll see if the electrician can wire me first a separate breaker box for out there, and second a hook up that I can flip a switch and come off outside power and onto indoor stored power. Not sure what that would entail but its looking at least next Spring before I can do it so I have time. Might also set a input from a exterior generator too. That way i'm not having to depend on extension cords.

Clouds are rolling in again. We're supposed to get 2-4 inches of rain in the next few hours here in St Louis. Hopefully I won't lose power again.