Renewable Energy Systems

Renewable Energy Hydro Power

HYDRO POWER (Micro scale for small streams)

Introduction Outlaws WARNING! Hydro less expensive? Simplicity No huge dams needed

Grid tied Hydro?

Determining power potential How much power do you need? Before you contact us.
 

Harris Turbine near Deposit, NY

Hydro electric power systems use many of the same system components as solar PV systems, therefore, combination systems are very practical to consider if a small stream or other source of water under pressure such as an artesian well is available. Water from a small stream, farm pond, springs, even artesian wells, etc. is diverted into a pipe and run down hill to the turbine site. The water  is nozzeled down and sprayed at a small pelton or turgo wheel turbine which turns an alternator or generator. One type of turbine is one that produces DC which can directly charge a battery bank (which can be shared with a solar array). Charging batteries with water power allows you to size the system for your average load and run off the batteries during your times of peak load. This makes it possible to make use of a smaller stream than would otherwise be possible. Typically a stream with either 50 feet or more of vertical drop across your site and 30 gallons per minute (gpm) or more, or a wide deep stream with high flow 100 gpm or more and a vertical drop of 12 feet or more are practical to consider for making electricity. With even greater flow rates lower head levels can be utilized with turbines specifically designed for low head sites. Low head sites may utilize a sluice way instead of a pipe line. The closer the turbine location to the building needing the power the better.

With the advent of UL listed and approved grid tie inverters it is now possible to directly Utility grid tie a micro-hydro site at relatively low cost and eliminate batteries. Now with Net Metering in NY the power company credits you at retail for your backfed energy. The advantage of this is maximum financial benefit. The disadvantage of this scheme is that when utility power is lost the system must shut down to prevent back feeding a dead utility grid and you have no power from your system. A dump load and a relay must be included in the system so when there is a utility outage hydro power is diverted to the dump load. Hydro Turbines must never be allowed to "free-wheel" and always have a load on them or they will burn out! If you want power from the system during a Utility outage you can have batteries as well as grid tie. This way the batteries will power your home when Utility power is not available.
The beauty of a battery-less system, however, is you have no heavy toxic batteries to deal with and your system is much more reliable than systems with aging batteries. In some states Utilities may be required to credit you at the same retail rate you pay them for any excess power produced. Its called Net Metering. We now have Net Metering for Hydro in New York. The rules are such, however, that it does not pay to over-produce. It may be best to keep the power you make for yourself by regulating your loads so they are constant and matched to the production. One way to do this is to electrically heat a large insulated tank of water 24-7 and draw off heat as needed by thermostat to heat radiant in floor heat. This helps save on your heating bills. However, you must realize that heating a home is a huge load and takes a large flow of water to drive a large enough turbine or multiple turbines to do it. For instance I just evaluated a site for a customer with 8 feet of head and 3400 Gallons per minute flow. He can drive two 1600 watt turbines with 3/4 of this flow. There are 3413 BTU of heat available for every 1000 watts of power. This means that he only has 10,900 BTU per hour available for heating his home from this 20 foot wide stream. Most homes require something in excess of 50,000 BTU/ Hr in the coldest weather. However, the coldest part of the winter is at most 10% of the heating season. 10,900 BTU-hr could significantly reduce heating bills during more mild parts of the heating season. So don't throw away your furnace.

• Legal note to OUTLAWS: Some in the USA associated with Micro scale DC hydro may technically be an outlaw, however, I was recently contacted by John W. Webster who says, "Everyone who has a hydroelectric station isn't necessarily subject to the FERC nightmare. If you don't sell power, you're exempt. If you're not on a navigable river (as defined by local authorities), you're exempt. Etc.etc.etc. I've been doing small hydro for going on 20 years. I deal with FERC on a daily basis." Every hydroelectric system whether it be 1 watt or 100 megawatts is subject to regulation by the Federal Energy Regulatory Commission (FERC), for those who sell the power. To operate a legal hydro system for profit one would have to file for a power license. This involves all kinds of studies, detailed construction plans and other paperwork that would cost you more to do than your project itself. These regulations were written for big power companies. Most local authorities realize that regulations intended for big companies don't apply to homeowners making power for themselves and will look the other way as long as no one complains. So be responsible and don't flood out your neighbors or dry up trout streams or in any way goof up aquatic habitat or block navigable rivers. Help all of us and keep yourself out of trouble so the authorities can continue not noticing us.
• I learn a lot from my customers who have gone through this. One hydro customer who is a retired DEC forest ranger has thoroughly researched how best to accomplish a small home hydro system. He recommends: Do NOT get a permit for your project! Instead secure the water rights to your land. Often getting a permit involves signing away your rights to the authorities! If you have full water rights you have a better footing in court when and if something goes wrong. Do not listen to the authorities when the claim a permit is required. It may not be so. Permitting is about protecting the authorities and not about protecting you. Water rights can be written into your deed. If the water source is on others land it may be possible to have your rights written into their deeds. Check your local division of land records. Perhaps water rights are already in the deeds. When water was sourced from springs and streams water rights were standard practice when buying and selling of land. If you want your water rights assured, hire a lawyer to do it for you.
• Warning! Remember, electricity can be dangerous. Respect it. It can burn and even kill you. Also, moving parts on a turbine can catch you and chew you up.

Micro scale hydroelectric systems are usually less expensive than Photovoltaic ( PV) (solar electric) systems (unless financial incentives are available) because for the same power output small turbine generators are a little less costly than PV panels. (However, PV panels don't ware out; Micro Hydro turbines being mechanical do, and pipe lines for hydro can be expensive.) The philosophy is to charge batteries with direct current (DC) and convert it to typical household AC with inverters). Check Outback Power site for more info on inverters. AC turbines exist but they need a stream big enough to produce power to meet your peak loads. With a battery bank and inverters sized to your peak load to charge continuously with a small DC turbine we can get by with a much smaller stream and pipe. Now in New York State with net metering (Spinning the utility meter backwards) it can be more cost effective than ever to own and operate a microhydro plant. Net metering makes it possible to eliminate the batteries from the system.

Micro scale hydroelectric systems are surprisingly simple. Much of the system can be installed by a do-it-yourselfer handy with tools, however, most of the electrical connections should be done by a professional familiar with the national electric code, low voltage high amperage DC wiring and common AC wiring practices (in particular any connections to the utility grid should be done by a licensed electrician). Please realize that micro-hydro turbines are NOT maintenance free. They require almost daily or at least weekly maintenance to keep penstock (pipe line or sluice way) intakes free of debris. They are not suitable for part time homes.

Micro hydro may not require a large dam to make power. All that is needed is a small dam big enough to divert water from a stream into a pipe and keep air and debris out. We divert the water as high as possible on the hill into a schedule 40 PVC pipe or a polyethylene pipe and run it down hill to the turbine location as low on the hill as possible and as close to the load as possible. In areas of prolonged winter freezing the pipe must be buried and/or insulated. Often laying the pipe in the stream completely submerged is sufficient to prevent freezing in milder climates. Low head sites may be an exception. Generally dams are required for low head sites.

Other sources of water under sufficient pressure often overlooked such as high pressure artesian wells can also be used.

The head (pressure) of the stream and the flow rate must be measured to determine how much power is available.

A small stream flow rate can be measured by temporarily diverting the water into a 5 gallon pail and timing how long it takes to fill. This should be done several times to get an average time. If time is in seconds the flow rate = 300 divided by the number of seconds to fill the pail. Another method helpful with larger streams is to measure and mark off a 20 foot section of stream free of debris and rocks, (better yet, a section of culvert pipe where the stream crosses a road), measure the average depth and width in feet. Toss in a floating object such as a stick of wood or a dry reed and time in seconds how long it takes to float down stream the 20 feet. Do this about ten times and take the average time. The flow rate = [(stream width ft. x avg. depth ft. x 20 ft) x 60 sec./ min] / the avg. number of seconds for floating objects to travel 20 feet. This is the flow rate in cubic feet per minute. To convert to gallons per minute, multiply by 7.48 gal./ cubic foot.

The pressure or head is the vertical height difference between the top of the pipe and the bottom. This can be measured with a transit. Or with a builders level at the highest point on the stream site on a tall object of known height at the bottom of the proposed pipe. This can be done in small steps and added by sighting on an object of known height such as a ten foot long 2x4. Another method is to measure the static pressure directly by diverting water at the top of the stream into a garden hose. Place the other end of the hose at the proposed bottom of the pipe, the turbine location, and place a pressure gauge on the down hill end. The measured pressure is the static head in psi (pounds per square inch). Be sure you allow the water to run through the hose to expel it of air before installing the pressure gage. Air in the line will give you false readings.

To get an idea of the power potential of your site multiply the Head (feet) x the Flow (gpm) and divide by 5.3 then multiply the result by 0.35 . The result is the approximate instantaneous wattage taking average efficiency losses into account. Pipe diameter and length also greatly affect this output. The longer and/or smaller the pipe the less the output. So keep your pipe run as short as possible and as big as you can afford (within limits). A 4 inch pipe is minimum!!! If you have more than 50 feet of head use a pipe type capable of holding the pressure without rupturing IE schedule 40 or schedule 80 PVC, Polyethylene SDR-11 or even steel pipe. Cheap drain pipe won't do! In most cases a 6 inch diameter pipe is far superior to a 4 inch one.

Armed with HEAD and FLOW information you are ready to contact us.

All of the electrical components of the system are the same as with wind or solar electric systems. The only difference is the hydro electric turbine and generator unit.

The other side of the issue is how much power do you need and how often for how long? A good place to start is with your current electric bill. What is your kilowatt hour usage per month? We need to know your average daily kwhr usage. This is your electric bill KWHR divided by the number of days the bill covered. Do this for a winter bill and a summer bill because your seasonal usage is probably different. Then divide the result by 24 hours to see what your average hourly KW usage is. This can be directly compared to the potential output of the turbine in your stream (as determined according to the above and the enclosed information). We have a load determination worksheet "Load Profile Form" for you to download and fill out to more precisely determine a load budget. This is a good exercise to get you to think about areas you could conserve and sometimes drastically reduce your current usage.

Even if you never install an independent power system, simple free conservation can save you a lot of money. Besides turning off lights when not needed people often overlook other power hungry devices. Did you know that those little black box power converters such as on battery chargers, answering machines, computers and cordless tools eat power 24 hours a day even if the box is left in the wall with the device unplugged? Unplug the black box from the wall when the device is unplugged or the battery is fully charged. Did you know that dust on the coil on the back of your refrigerator and freezers can make the unit a lot less efficient and shorten its life? It pays to vacuum off the dust on the back of your refrigerator at least twice a year. Most people never do this because they can't see the dust accumulation with the fridge against the wall. If your fridge is installed in a place where it can't breath you shorten its life and reduce its operating efficiency. I.E. if your fridge is surrounded by a cabinet, make changes to allow good air circulation around the back of the fridge, there should be a noticeable drop in your electric consumption.

Every site is different and requires a  system uniquely designed for it in order to maximize the power potential for that site.

We can help you most if you provide us with the following information when you contact us:

1. The head (elevation height difference between the proposed pipe inlet and outlet) or the measured pressure
2. The Flow rate of the water in Gallons per minute, or liters per minute
3. The proposed pipe length along the ground from top to turbine location at the bottom
4. The distance between the turbine location and the house or building where the power is to be used.
5. Do you already have a dam on the site?

What is HEAD and FLOW?

Without this very basic information we cannot quote system prices since every site is different.

Let us know if we can be of further assistance.

For more free information contact us . The first e-mail consultation is FREE. so let us know a little about your project (at least the required info listed above).