Electricity Saving Tips For Homes And Offices

Net Metering policy for roof top PVs in various states in India

By on August 12, 2016


Solar powered systems can be categorized in two:

  • Grid connected solar power system.
  • Stand alone Offgrid system.

A grid connected system as the name suggests is the one in which your solar power system is connected to the local main grid. In this case, your loads can run on solar power as long as there is sufficient energy available from the sun during the day. Any deficit is taken care by the main utility supply. However, if the solar energy production is in excess as compared to the load requirement at that moment, the excess energy can be either stored in the batteries (if available) or can be sold back to the utility grid. This difference of energy can be tracked using a meter connected to your solar pv system.


Types of Metering

In a solar powered system, usually following two types metering systems are involved:

  • Gross metering
  • Net Metering

In gross metering, entire energy generated by the solar PV system is fed back directly into the utility grid.  In this case, the owner gets incentives based on feed-in tariffs proportional to the energy fed back to the grid.

However, net metering takes into account the difference of excess energy fed back to the grid and total energy consumed from the grid by the system owner. A detailed explanation about net metering is given below:

What is net metering?

Net metering is an agreement that allows the solar PV system owner to sell excess solar energy to the utility company or buy deficit energy from the utility company using a meter to track this energy exchange.

Following 2 cases take place in this scenario:

Case 1: If at any moment of time, if solar energy generation (kWh) is less than the load requirement at that time, the difference of energy is taken from the main grid and the meter runs forward, as usual. In this case, the system owner is charged for the units (kWh) consumed from the main grid. Eg. During early morning or during late evening/night.

Case 2: If at any moment of time, if solar energy generation (kWh) is more than the load requirement at that time, the excess solar energy is fed back to the main grid and the meter now runs backward. In this case, the system owner gets credit for the units (kWh) fed back to the main grid. Eg. During peak sunshine hours (afternoon)

NetMeter
When you generate extra electricity (more than what you can use) the meter literally moves backwards.

Thus, at the end of the billing period:

If case 1 > case 2, then the owner is charged for the difference of units as per usual retail tariff

If case1 < case 2, then the difference of units is either carried forward to the next billing period or the owner is paid for the difference of units as per the tariff decided by the concerned utility.

(kindly refer your state policy/utility company policy for more information about tariff)

In short, the owner pays/gains for the ‘net’ energy used over the designated period of time.

Meters used in Net metering:

The use of meters in this case differs from State to State. Some states may require only one meter that reads the ‘net’ energy consumed by the system owner. However, few other states may require two meters – one to measure solar energy generation and the second to measure the units consumed from the utility grid.

(Kindly refer your state policy for more information about tariff)

Advantages of Net Metering:

The 3 most important advantages of net metering are:

1. Financial benefit for the system owner

Since the system owner is charged for the net energy consumed from the utility grid, the owner gets financial benefits. Eg. If energy generation < energy consumed: owner pays just for the net amount. If energy generation > energy consumed: the owner gets credit for excess generation.

2. Avoid the use of batteries

In a grid connected solar pv system, any excess energy generated can be fed back to local utility grid and can be taken back at later stage when required. Thus, there is no need to store the surplus energy in batteries for later use, thus, avoiding the heavy costs of batteries. Also, since batteries are eliminated, the maintenance costs of the system also reduce to a great extent. Batteries may be required only when there are frequent power fluctuations/outages. (please note, in a batteryless grid connected system, if there is an power outage and the grid fails, your solar power system has to stop generating power to ensure safety of the wiremen working on the failed gridlines.)

3. Produce more today, use that tomorrow

Typically, a solar power system produces more energy in summer and comparatively less energy in winter. Eg. If in summer, solar power generates 100 units and load requirement is 80 units, then 20 units  can be fed back to the grid. In winter, solar power generates only 60 units and load requirement is 80 units, then 20 units can be taken from the grid. Thus, overall excess generation from solar power system is taken care of and net units consumed from the grid becomes zero.

Net metering in various states across India

As of date, 30 states and UTs in India have implemented the policy to support “Grid Connected” Solar PV. For now, we’ve just put in the links to their policy and tariff documents (as sourced from MNRE website) in the following table, but we will try to explain each of them in our future posts.

Sl. No. States State Policy for Grid Connected Solar Rooftop SERC Regulatory/ Tariff Order
1 Andhra Pradesh Andhra Pradesh Solar Policy 2015 APERC Order 2010 APERC Amendment 2010Andhra Pradesh Amendment Net Metering
2 Assam Assam Electricity Regulatory Commission’s Grid Interactive Solar PV Regulations 2015 dated 02.05.2015
3 Bihar Bihar State Electricity Regulatory Commissions Net-metering Regulation dated 7th July, 2015
4 Chhattisgarh Chhattisgarh Solar Energy Policy 2012-2017 Chhattisgarh Tariff Order for procurement of power from Rooftop PV Solar Power Projects by distribution licensees of State Regulations, 2013 Order for Connectivity and Distribution Charges for Solar Rooftop PV Projects – Issued on 29/10/2014
5 Delhi —- Delhi Electricity Regulatory Commission (Net Metering for Renewable Energy) Regulations, 2014 Guidelines under DERC (Net Metering for Renewable Energy) Regulations, 2014Brief Note on Guidelines under DERC (Net Metering for Renewable Energy) Regulations, 2014
6 Gujarat Gujarat Solar Power Policy 2015 Gujarat Solar Tariff Order 2012
7 Haryana Haryana Solar Policy 2014 Order for SPV Power Plants for Building/Areas of Haryana GovernmentRegulations for the Grid Connected Solar Rooftop Photovoltaic System
8 Himachal Pradesh Himachal Pradesh Solar Power Policy Himachal Pradesh Electricity Regulatory Commission Notification 2015
9 Jharkhand Jharkhand Solar Power Policy 2015
10 Karnataka Karnataka Solar Policy 2014-2021 Karnataka Tariff Final Order 09.10.2013
11 Kerala Kerala Solar Policy 2013 Kerala KERC Order 10.06.2014
12 Madhya Pradesh Madhya Pradesh Electricity Regulatory Commission (Grid connected Net Metering) Regulations, 2015
13 Maharashtra Maharashtra Electricity Regulatory Commission (Net Metering for Roof-top Solar Photo Voltaic Systems) Regulations, 2015
14 Manipur Manipur Solar Policy 2014
15 Meghalaya Meghalaya State Electricity Regulatory Commission Notification 2015
16 Orissa Net Metering/Bi-Directional Metering & their Connectivity for Rooftop Solar PV Projects Dated 26.11.2014
17 Punjab Punjab Solar Rooftop Policy 2014 Punjab State Electricity Regulatory Commission Notification,7th May, 2015
18 Rajasthan Rajasthan Solar Energy Policy, 2014 Connectivity and Net Metering for Grid Interactive Rooftop and Solar Systems, Regulations, 2015
19 Tamil Nadu Tamil Nadu Solar Energy Policy 2012 Tamil Nadu TNERC Order 7.3.2013Tamil Nadu TNERC Amendment Order 31.07.2013
20 Telangana Telangana Solar Power Policy 2015
21 Uttar Pradesh Uttar Pradesh Rooftop Solar Photovoltaic Power Plant Policy, 2014 Uttar Pradesh Electricity Regulatory Commission (Rooftop Solar PV Grid Interactive Systems Gross / Net Metering) Regulations, 2015
22 Uttarakhand Uttarakhand Solar Policy 2013 Uttarakhand Tariff Order 2013
23 West Bengal West Bengal Solar Policy 2012 West Bengal WBERC Notification 2013
24 Andaman and Nicobar Joint Electricity Regulatory Commission for the state of Goa and Union Territories (Solar Power – Grid Connected Ground Mounted and Solar Rooftop and Metering Regulations – 2014) and Solar Power Tariff
25 Chandigarh
26 Dadar and Nagar Haveli
27 Daman and Diu
28 Lakshadweep
29 Pondicherry Puducherry Solar Energy Policy 2015(notified on 01-03.2016)
30 Goa

References

http://www1.eere.energy.gov/solar/pdfs/31687.pdf

http://www.forumofregulators.gov.in/Data/HomePage/Report.pdf

http://www1.eere.energy.gov/solar/pdfs/31687.pdf

http://www.solarcity.com/learn/understanding-netmetering.aspx




Recommended Content

Top

Send this to a friend