Solar power can be produced only during day time, mainly from 8 AM to 4 PM. Most of houses, hospitals, shops, malls, hotels , clubs have major power consumption in the evening. So in case you wish to go green, you have to store power in battery and use it in night. This system is less efficient, involves regular maintenance of batteries, recurring cost of replacement of batteries. More over batteries are not environment friendly. Hence battery free system was required. This is achieved by Net Metering.
Solar power required for the complete day + Night is generated during the day. Excess power is fed back to DISCOM Grid & remains as a deposit with them. You will use electricity in night. No of units deposited ( say 10 units ) during the night will be reduced from the bill for No of units consumed in night (say 12 units ) So DISCOM will charge you only for 2 units. This is Net total of units hence called as Net Metering.
Refer to the graphs below. Red line shows the typical solar power generation against the time line and the blue line shows the power requirement. Fig 1 shows typical power requirements & solar generation for Offices & Fig 2 shows typical power requirements & solar generation for Homes.
Area marked yellow "A" is excess power generated from Sun and the pink area "B" shows the power shortage from sun. Now in ideal situation, A should be equal to B. Excess solar power (A) is fed back to grid and is adjusted against the power consumption (B). This is achieved by net metering.
Sum the consumption in no of units per month for past 12 months, divide it by 12 , you will get your monthly average consumption. Use the following chart to decide which solar power generator you want to install.
|Average Monthly Units||Aprox area reqd||Inverter Required||SPV Capacity (wp)|
|300||350 sft||3 Kw/1 ph||2500|
|500||600 sft||6 Kw/3 ph||4200|
|800||1000 sft||10 Kw/3 ph||7200|
|1000||1300 sft||10 Kw /3ph||9000|
|1500||1900 sft||10 Kw/3 ph||13500|
|2000||2400 sft||15 kw/3 ph||18000|
|2500||3100 sft||20 kw/3 ph||21600|
|3000||3700 sft||20 kw/3 ph||27000|
Suppose you get your average monthly consumption works out to say 627 units. Then you have choice to select lower model of 500 units per month & opt to pay little every month to your DISCOM. In case you have future plans which will result in increase in power consumption, you can opt for higher model say 800 units per month. In case you to wish to have near to exact production, contact a Project developer who will do exact calculations & give you a quote OR write to us at firstname.lastname@example.org. Now cross check the area required to achieve your estimated production. There can be case where your need is high but the shadow free roof top available with you is less, then you will have to settle for lower capacity.
No. No matter what you produce, your bill can never be zero. You will still be paying meter rent, minimum commitment charges etc as per your agreement with DISCOM.
If you are making your balance sheet and profit & Loss account, you can claim 80% accelerated depreciation under the present laws till 30 sept 2016, there after it would be 40% +40%+20%. But we suggest, pl check the same with relevant authority / consultant before making any buying decision.
Rate per unit differs as per the category of consumer as well as slab of power consumption. Pl divide the final amount you pay to DISCOM by no of units shown in that bill. You will get your average rate. Multiply the same with estimated average monthly consumption shown in the chart and you will get your monthly saving. Deduct cash flow advantage of 80% depreciation ( in case applicable ), which works out to appox 27% of the project cost by rule of thumb from the investment cost, divide it by saving per month and you will know in how many months you are recovering the cost.
For a 1000 units/ month plant, your investment could be typically Rs7.2 Lacks
Less cash flow advantage (27% of investment ) = Rs 1,94,400
Net Project cost to you ( 7,20,000 1,87,200) = 5,25,600
Now if your average rate is say Rs 11.35 per unit , monthly cost for power produced by you would be Rs 11,350/- And hence you will require 46.3 month i.e. 3 yrs & 4 months to recover your cost from saving in electricity bill.
In case you have done your project thro a experienced and reliable vendor, there is virtually no maintenance required except regular cleaning of panels.
Solar panel manufacturers generally give 25 yrs performance Warrantee. And any reputed make inverter will give you 5 yrs warrantee. In case you wish to give your project under AMC, they will generally chare you 1.5% of the project cost annually.
- Maximum limit is 1 MW.
- Your generation cannot be more than the sanctioned load This is to take care of the service line that supplies power to you from the nearest distribution transformer.
- DISCOM will not allow you to inject power more than 40% of the capacity of Distribution Transformer which is feeding you power. However they have powers to assess the load on transformer during day & night time and exceed the capacity or change the transformer to higher capacity.
- In case you have large premises, you can have decentralised generation on multiple buildings but the sum of all generations will not exceed the sanctioned capacity.
- Connectivity voltages
- up to 8 kw 230 V
- Above 8 kw but lower than 80 kw ( 150 kw in municipal corn area) 415 V
- Above 80 kw 11 kv
In case you have your private transformer, you can grid tie at LT level
Pl refer to http://www.balgo.co.in/howsolarpower.htm
Pl down load : http://www.balgo.co.in/pdf/net metering leaflet.pdf
Need More details on Net Metering .. visit U tube link :
- Go to the web site of your DISCOM & down load the application form.
- Fill in the required details & attach necessary documents and submit with registration fees as per your category ( Rs 500/- up to 5kw & Rs 1000/- for others).
- Get your net metering sanction letter from DISCOM.
- Select a reliable vendor from your area and finalise the contract with them.
- Once the project is ready, they will give you test certificate and also the clearance from Electrical Inspector ( If applicable) submit the same with your letter to DISCOM along with stamp paper agreement ( available on most of DISCOM web site ).
- DISCOM will inspect the installation and grant you the permission for connectivity and execute the stamp paper agreement. They will also replace your present normal meter with Bi directional Net Meter.