SKY- Suryashakti Kisan Yojana

The Gujarat government on Saturday launched a solar power scheme for farmers- Suryashakti Kisan Yojana (SKY) enabling them to generate electricity for their captive consumption as well as sell the surplus power to the grid and earn an extra buck.

Announcing the pilot project of the scheme in Gandhinagar, chief minister Vijay Rupani termed it a revolutionary step towards empowering farmers to generate their own electricity using solar energy and help doubling their income.

As per the scheme, farmers having existing electricity connection will be given solar panels as per their load requirements. The State and Central governments will give 60 per cent subsidy on the cost of project. The farmer is required to take 5 per cent cost, while 35 per cent will be provided to him as an affordable loan with interest rates of 4.5-6 per cent. The scheme duration is 25 years, which is split between 7-year period and 18-year period.

"For the first 7 years, farmers will get per unit rate of Rs 7 (Rs 3.5 by GUVNL + Rs 3.5 by state govt). For the subsequent 18 years they will get the rate of Rs 3.5 for each unit sold," said Saurabh Patel, State Energy Minister.

The move is being seen as an attempt to pacify the farmers, who are reportedly angry with the ruling party.

Below is the link for the media session of Gujarat CM for announcement of Suryashakti Kisan Yojana, click here. To know more about subsidy, read MNRE Rooftop Solar Power Plant Subsidy Scheme.

What is 1 kW ?

What does 1 kW means? For many it is quite simple but in reality it is not. As per definition, 1 KiloWatt is a unit of energy which transmitted or used at a constant rate (power) over a period of time. The total energy in kilowatt hours is equal to the power in kilowatts multiplied by the time in hours.

When we are talking in reference to solar system then, 1 kW can be expounded in two way- 1 kW AC and 1 kW DC. There is difference between 1 kW and 1 kWp. Actually, 1 kW means 1 kW AC which is general is  misconceive as 1 kW DC. 1 kW  DC is  represented as 1 kWp. 

1 kW AC is 1000 watts of AC power generated by converting DC power through Solar Inverter. It is equal to capacity of Solar Inverter. On other hand, 1 kWp mean 1000 watt of DC peak power. It is maximum DC power generated by solar modules and is equal to total capacity of solar modules.

Example: 308 nos. of 325 Wp solar panel with 2 nos. of 50 kW solar inverter. In this case, DC capacity would be 100.10 kWp and AC capacity would be 100 kW. The difference is noticeable through above example. The ratio of DC capacity to AC capacity is called over-loading or under-loading.

So, next time if someone says 1 kW, do question him/ her  whether he means AC or DC.

South VS East-West orientation

The sun as we know rises in east and sets in west. Additionally, it also changes is position (season wise) in sky with respect to a fixed point on earth. The orientation of solar module may be defined by two parameters namely azimuth and tilt angle. Tilt angle of solar module is defined as angle between the horizontal ground and the solar module. Azimuth angle of solar module is an indicator of alignment of the module with respect to (true) south. For modules facing (true) south this angle is Degree and for module facing (true) north this angle is +/- 180 Degree.

The most common methodology of module orientation and the most efficient one wherein the module is oriented in southwards direction. With southwards orientation, sun can be tracked to its maximum limit, thus generating maximum energy. However, a major drawback with this type of orientation is that it requires a larger area and also leads to shadow losses. To reduce shadow losses, system needs to be designed in such a way that no solar plates in one row cast a shadow on another at any point of time. With this orientation, the tilt angle widens, increasing the pitch and reducing the available space. Modules installed in southward orientation are favorable for places with high energy demand. 

East- west orientation of modules is the best method to optimally utilize the available space. On flat roofs, this orientation has the capability of maximizing the number of PV modules in a way that they don’t cast a shadow on each other. Through this method, solar PV systems can be installed on East-West-oriented (E-W) or slanted roofs as well.

Advantages of E-W Orientation

• More Installed Capacity

Over 20-30 percent more capacity can be installed in the given area. This is because only walking space is left between the arrays instead of shading elimination.

• Higher yield per sq. m

Since higher capacity installed in a given area therefore there would be higher yield.

• Even distribution

The generation of east facing modules would be a mirror image of modules facing west. This would form a bell curve, distributing the generation evenly.

Advantages	Disadvantages
More Capacity in specified area	High mismatch losses
Higher generation per sq. meter	Lower specific production
Even distribution of generation	Increase in number of inverter
Reduction in Wind Load	Lower Return on Investment

Below are the results of simulation run through PVsyst:

E-W Orientation

South Orientation

To conclude it is important to check and verify the feasibility of the orientation used in module installations. Before finalizing the orientation, it is critical to understand the load profile calculations and building architecture. In case of a challenging building architecture and energy demands/costs, East-West orientation may fetch attractive results. It is true that E-W orientation substantially increases the DC capacity of installations by nearly 33 percent on the same size of roof than southward orientation and also results in considerable amount of power generation. E-W orientation can definitely prove to be a useful method in harvesting solar energy on challenging rooftop structures.

GRIHA: Renewable Energy Utilization- A step towards sustainability

GRIHA is an acronym for Green Rating for Integrated Habitat Assessment. GRIHA Council, is an independent platform (registered as a society) for the interaction on scientific and administrative issues related to sustainable habitats in the Indian context. GRIHA Council, is mandated to promote development of buildings and habitats in India through GRIHA. It was founded by TERI (The Energy and Resources Institute, New Delhi) with support from MNRE (Ministry of New and Renewable Energy, Government of India) along with a handful of experts in the sustainability of built environment from across the country. 

In this blog we will be discussing on Energy section of GRIHA out of may other section which will include points and ways to sffirm them."Renewable Energy Utilization" criterion is a part of Energy section. The purpose of of this criterion is to ensure that building incorporate renewable energy as a source in the project and partially or completely get independent from the conventional source of energy such as coal petroleum etc. By fulfilling the criterion, a project can claim maximum of 7 points.  This criterion contributes 7% of total points.

In order to claim points in this criteria, a project has to meet below mentioned conditions:

• On-site/Off-site renewable energy system installation to offset a part of the annual energy consumption of internal artificial lighting and HVAC systems as mentioned in the table below: 

Daytime Commercial/ Institutional Buildings	Residential Buildings	24 X 7 occupied buildings	Points
2.5% (only On-site)	-	0.5% (only On-site)	Mandatory
5%	5%	1%	1
10%	10%	3%	2
15%	15%	5%	4
20%	20%	7%	5
25%	25%	10%	7

                                                                             OR

• Off-site renewable energy system to offset 100% building energy demand (this appraisal is available for only non-residential buildings) – Mandatory +7 points 

If the project is meeting the above mentioned conditions, following documents has to be submitted. The nature of documents can change but the purpose needs to be fulfilled in order to claim points

• Calculations/simulations for renewable energy system sizing & on-site annual energy generation potential. 

• Specification sheets and purchase orders (reflecting full quantities) of the renewable energy system, highlighting the panel performance (as tested under standard test conditions). 

• Drawings in CAD format to show location of renewable energy systems. 

• Documents supporting off-site generation of energy through renewable energy systems. These may be either: Renewable Energy Certificates (RECs) for at least 2 years along with a declaration that the RECs are not being used for any other obligatory requirements and will be purchased every year OR Power Purchase Agreement from the utility for purchase of green power. In the agreement, the address of the particular site must be mentioned. 

• Photographs, with description, of the measures implemented.

For more details on green building and its other criterion visit GRIHA website. To download copy of GRIHA manual V 2015, click here

Har Ghar Solar: Grid Connected

We all understand the benefits of solar energy. Currently, it is the hot topic among residential sector. And why not? With reducing price of Solar system and constant support from government on form of subsidies, it is great time to invest on SOLAR and enjoy butter for next 25 years.

Tea is best prepared when one knows about the quantity of ingredients to be added. So, the question is HOW MUCH? How much capacity of solar system can you install in your premise. In the current blog, we will be talking about grid connected Solar PV system. The capacity of system is dependent on the load of the consumer. In simpler words, it is dependent on how much appliances one use during the day.

In the below example, we have considered a typical 2 BHK house with basic electrical appliances.

Let’s assume that the below chart represents consumption of a house in a day;

Equipment	Quantity	Power Consumption (W)	No. of Hours	Total consumption (Wh)
Fan	3	50	6	900
Tube light	3	35	6	630
CFL	3	12	8	288
AC	1	1200	4	4800
Washing Machine	1	750	0.5	375
Refrigerator	1	150	10	1500
Miscellaneous	1	200	1	200
Total Consumption				8693
Margin@10%				869.3
Total Consumption in kWh				9.56

A typical solar system with capacity of 1 kWp generates 3.5-4 kWh. The solar calculator by NREL; PVWatt gives consumer an idea about the annual generation by solar PV system.  Considering the same, a solar system of 2-2.5 kWp would be sufficient for the above table. One need to consider peak consumption during the day.

A better and accurate method to calculate the load would be an electricity bill. Analyse the electricity bill to find monthly consumption & daily peak consumption and accordingly install the PV system.

Apart from the consumption of the house there are some other factors which has to be considered while determining capacity of the system, such as:

Sanctioned Load

This can be determine by going through the electricity bill. Government allows only a percentage of total sanctioned load to be capacity of system. Kindly refer the solar state policy to know the allowed percentage.

Shadow Free Area

One of the key factor when it comes to installing solar system is shadow free area. Shading on single module affects the performance of whole string by increasing shading loss. Hence it is important to identify area without obstacle before installation. To install 1 kWp of system, approx. 100-125 sq.ft. is needed.

  

     Orientation of House

This is one factor which is not in your control. There are scenario where the house/ flat are not facing true south. In such cases, it is advised to change the orientation of the system to true south to achieve maximum output. This would definitely reduce the capacity of the system which you could have installed in orientation of house.