Peter VanDerWal wrote:For the majority of microhydro generators, more head is generally better than more flow (typically better efficiency).
Intercept stream A as high as you can and run it through pipes to a microhydro generator positioned as low as possible.
I totally agree that a backup generator is a great thing to have. And i will most likely have one in future years. Its just not on my top list of things to get right away. like the solar panel. i am eventually going to have one, and it will be a great supplemental power source but i question if i have enough sun to justify buying one right off hand. and keep in mind, budget is TIGHT.S Bengi wrote:The $1400 price point looks very attractive and will probably do the job that it was created for.
My price of $4000 ($6,000 if I include solar panel and emergency gas generator), is so high because of quality and use case.
Inverter
If all I need to do is power a pump or drill then any cheap inverter will work, but if
I want one what will not damage electronic like laptop, computers, tv, etc, it will have to create a pure sine wave ac
If I only plan on using it once in a while then a cheap one will do, but if I am going to have it on 24/7 year after year, A more expensive one with components rated for 24/7 is needed.
If I only plan on only pulling a max power of 1000watt, I can use a cheap one but if I envision my lights+tv+computer+pump+microwave+fridge+etc all on at the same time. It will then necessitate of 4000watts.
If I am going to have motors/etc running then I have to also worry about surge power(of say 6000w) and not just rated power(of say 4000w).
Battery
You should only discharge a battery to 50% so you really need to double your rated storage capacity.
Once you battery reaches 75% full the efficiency drops and as you approach 99% full more than 50% of the power going into it is wasted, so you really need your battery at 3x your rated storage need.
If you want your battery to store enough power for 3 or so days in case of emergency then you need at least 9x
Hydro-Generator
From flow*head calculation to actual loads in the house the combined efficiency is only 55% or less. So your 1440w per day is now down to only 720w per day or less, so a solar panel actually makes alot of sense.
Even going with a cheap microhydro, there is alot of misc cost such as wire, pcv pipe, bolts, structures, case, possible earthworks, electrician, etc I pretty much included some misc cost into it.
Charge Controller
If one were to supplement the microhyrdo with solar, then a more robust charge controller is needed that can accept power from both hydro and solar. It would also need to be mppt to accommodate constantly changing sunlight condition on each panel.
Solar
Solar Panel are actually pretty cheap at less than $1 per 1watt/hr or $1 for 4watt/day.
Backup Generator
Gas/Propane/LNG generator is only 45lbs so very portable, it is super quite at only 49decibel and with 1gallon lasting 4hr-10hr. It is pretty economical. But why would you need it. So that you can run some tools when you are away from the house, so that you can car camp in real style or power a RV, so that you have a power source if you other options are unavailable, etc
S Bengi wrote:everywhere you see 1k substitute it for $1,000.
So the entire setup cost $6,000. $1000 for the gas generator, another $1,000 for the battery, another $2,000 for the charge controller and inverter, another $1000 for the solar panel, etc.
S Bengi wrote:hydro generator+solar panel>>charge controller>>battery>>inverter>>house/load.
If for whatever reason you can't produce enough electricity you can then plug the grid into the inverter to fill up the battery, or you can use a gas generator, if the grid goes down.
hydro generator=$1,000 aka 1k (1440w per day....60w*24hr)
solar= 1k (4000w per day ......1000w*4hr)
charge controller + inverter =2k
battery = 1k (8kwhr can be 80% discharged vs the usual 50%)
honda gas/propane generator =1k (2000w surge, 1600 rated and 1000w eco/quite mode @only 49 decibel)
Joseph Lofthouse wrote:I am a scientist, so I understand the physics of water and electricity. I'm also a subsistence farmer living under a vow of poverty, so I don't have a clue about what consumer goods are available.
If it were me, and I wanted a grid-tied system. I would build a stand-alone system to power an appliance or two, or one circuit. Then when the battery was full, dump the excess power onto the house mains through one of those micro feed-only grid-tied inverters. And if the system was generating more power than the rest of your house was using then the excess would end up on the grid. If the battery got too low during normal usage, then it could be filled with a battery charger powered by the grid.
60 watts is very low power today, but if the grid went down, it would be a treasure.
Joseph Lofthouse wrote:
Paul Delaet wrote:Can you explain how you calculated that? if i am making 60 watts instantaneously and that would be 1.4kw daily wouldnt that be 116ish amps daily.
Amps is an instantaneous measurement of current. It speaks to how big the wires in your system need to be before they melt.
Amp-hours is a measurement of how much energy can be stored in a battery. For example, a 100 amp-hour battery can deliver 1 amp for 100 hours, or 10 amps for 10 hours.
Watts = Voltage X Amps
So if you have a 60 watt output from your generator, and it is running a 12 volt system, then the system is producing 5 amps (60 watts/12 volts). If the system runs for 24 hours, then it is producing 120 Amp-hours per day. Oops. I sure messed up that calculation from a few posts ago. Sorry about that.
Joseph wrote:So it would take 20 days to charge a 100 amp-hour battery bank at 12 volts using this generator.
It would take 40 days to charge a 100 amp-hour battery bank at 24 volts.
What I should have written is:
So it would take 20 hours to charge a 100 amp-hour battery bank at 12 volts using this generator.
It would take 40 hours to charge a 100 amp-hour battery bank at 24 volts.
allen lumley wrote:- Just trying to put a little spin on a comment about 'little refrigerators'' not trying to highjack this thread ! Please not that those small refrigerators that college students
like to have in their dorm rooms are Generally NOT energy efficient, and often use more Electricity than a full sized Fridge -
The best refrigerators are Chest type refrigerators that open from the top. This has the additional benefit that the cold air doesn't fall out of the fridge as soon as you
open the door. Just my two cents ! Big AL
Can you explain how you calculated that? if i am making 60 watts instantaneously and that would be 1.4kw daily wouldnt that be 116ish amps daily.Joseph Lofthouse wrote:watts is the instantaneous power being generated. Chargers and inverters are sized to meet the maximum instantaneous power. The time they are operational doesn't matter.
watt-hours is the amount of power generated over time. In other words, watt-hours doesn't apply to chargers and inverters.
The watts stay the same regardless of any changes in voltage. In other words, the amount of water falling doesn't change regardless of the form of the electricty. So you don't double the watts if you double the voltage.
60 watts equals 5 amps at 12 volts.
60 watts equals 2.5 amps at 24 volts.
So it would take 20 days to charge a 100 amp-hour battery bank at 12 volts using this generator.
It would take 40 days to charge a 100 amp-hour battery bank at 24 volts.