Has anyone installed off-grid solar+wind hybrid system? My farm has unobstructed sun exposure for at least 8 months. During the monsoon months the wind turbine will be used to generate the power. The nearest utility line is HT 11kV and 1 km away. The cost of laying the line along with step down transformer is significant. And this is not an agri feeder so state utility will treat me as domestic LT customer (expensive).
The load is:
Submersible pump (1.5 HP), 270 ft deep + 90 feet delivery head (to a tank on small hillock about 400 feet away). The water will be circulated using gravity fed drip.
Lighting load - Farm house and servant quarter; 5 rooms together. (lights and fans and possibly one TV set), and a couple of lights in the yard.
I understand the practical difficulty for you to get a agri line commissioned to your farm.
Also, appreciate your thought about renewable energy.
In my practical experience I have personally seen many hybrid systems fail because of various issues like improper system design and maintenance on moving wind mill parts.
Hence we have and always recommend pure solar design as it saves money on maintenance costs.Expecially for lower capitive use projects.
The basic bill of materials in any offgrid project based on load in watts & watthours would be
A)Power source to generate required watthours (either solar or wind or solar+wind)
B)Inverter matching your peak connected load
C)Battery to store generated energy
As you can see B & C will be constant irrespective of option you choose in A.
So,To overcome the less power generating days you can always add up additional solar panels or have a tracking system for solar panels.
Email me or do call me for a brief discussion. I am sure we can offer you a solution that can meet your technical vis a vis commercial needs.
Is there a thumb rule to decide on additional solar panels required to offset the reduced generation on cloudy/rainy days? If the effect of cloudy/rainy day can be eliminated by adding additional solar panels then wind turbine may not be required. That would be much preferred.
I would like to run the borewell pump directly via inverter during day time. When pump is not running the energy will be saved in a battery pack for residential use.
There is absolutely no thumb rule as such, as the amount of solar panels additionally required to offset power drop would be directly dependent on amount of reduction in radiation which could never be predicted.
But having said that its always advisable to have atleast 25% more capacity to compensate for the losses (The more the additional panels the less the power drop). You can even add 50% more as long as it fits your budget.
First I need to design a system for your power requirement, which would itself clear your doubts.
Please let me know;
A)Is your 1.5Hp motor single phase or 3 phase?
B)How long would you run this on an avg a day in hrs max?
C)Would 5 tubelights, 5 fans, 1 TV & 2 CFLS suffucient for the farmhouse and servant quarters?
D)Do you also have Grid supply?
As this topic is at least 6 month old i hope you have come to some decision about Solar, solar-wind hybrid. Just in case I will put down my thoughts based on the experience we had putting up a 3 KV solar generation facility at our farm house in chikkbalapur district karnataka.
I must point out that this is for domestic use and not for powering a farm , having said that i must also point out that theortically i see no great diffrence in both. The reason for such high capacity is the system has to have enough backup capacity 6 hrs minimum to keep 2 refrigerators and a couple of other heavy appliances running. The main challenge i see with solar is the battery backup system this really adds on close to 40% extra on the capital outlay added to this you will need to factor a refresh/replacement cycle of approx 3-4 years for the batteries. Without the batteries solar makes perfect fitment to your kind of off grid setup. In the case initial capital is not a challenge u ciuld look at CSP concentrated solar power. I believe it has become viable for practical deployment the solat policy 2014 in karnataka talks of paying a price of 9 ₹ per unit fed by roof top pv generation. Vs 12 ₹ for power from csp. I guess u willneed to validate this with a proffessional. One methord used to avoid batteries is to heat up a very dense liquid in the daytime and tgis heat is then used to run a steam turbine . I understand that shirdi sai baba temple uses csp for all its cooking
Solar wind hybrid
I happened to explore the opportunity solar-wind hybrid to use for a polhouse i plan to put up this year i came across a company called Wind stream technologies which has productised this into 1 KW modules what impressed me most is unlike convential wind turbines this turbine starts generating with wind speeds as low as 3 km/sec with the solar panels on top of the turbines hence the footprint is very small. This again theortically can avoid the usage of batteries at night as the wind speed might be sufficient to handle light loads like lighting, fan, tv ect in the night.