RENERGY 2014 – Solar Training

Date: 14 – 06 – 2014

Session – 2 (SWELECT)1. Introduces Swelect and its subsidiaries, their certifications and also their achievements.2. Basics of Solar PV

a. Sun is source of all energy directly or indirectlyb. Irradiation is measured in kWh/m2 / dayc. PV is light dependent and not heat dependentd. Each Silicon based solar cell produces 0.5 V.

3. Solar Rooftop Solutionsa. Standalone systems – does not have additional power sources other than the solar

panels. E.g. solar street lights.b. Hybrid Systems – has many sources of energy ( a few systems were shown)c. Grid-tied systems – Supports load and pumps excess into the gridd. Bi-directional grid tied systems – they are grid-tied hybrid systems

4. Case Study (Solverminds – RCC roof)a. Must know orientation of building as solar system has to be south facing (true

south).b. Structure should be in optimum tilt angle (approximately the latitude angle).c. For RCC roofs conventional fixed tilt structure or elevated structures.d. Penetrating structures are not always required.e. Structures are designed to withstand wind speed of about 150 km/h.f. Even elevated structures are designed to withstand wind loads.g. Modules can also be installed on metallic sheet roofs provided the roof is strong

enough to support the load.h. Modules can also be technically installed on asbestos sheet roof, but it is advised not

to install the panels on them.i. Mounting structures are used to orient the panels to true south directionj. Only shade free area of the roof affects the sizing of a solar PV power plant.k. Plant Capacity depends upon usable area of the roof.l. Energy Generation = plant capacity * sunshine hours * performance factor

i. Energy generation = 80kW *6 * 0.7 = 336 unitsii. Annual energy generation = energy generation* sunny days = 336*365

=122640 unitsm. Designing the PV system

i. Identify critical and non-critical loads.ii. The load connected to the inverter depends upon the inverter rating

iii. Rewiring may be required if critical and non-critical loads are not segregated.

iv. Only surplus energy is supplied to non-critical loads.v. System should be sized with regard to load (critical load).

vi. Inverter is sized based on load and is sized 20 to 30% above actual requirement.

vii. Multi-inverter system can be used to segregate loads better at the cost of reduced efficiency.

n. Issues in PV power plantsi. Weight of components (inverters and battery bank)

ii. Distance between panel and inverters, and inverters and batteries.iii. Sizing of cablesiv. Dust accumulation and general maintenance.

o. Question and answer session with the participants

Session – 3 (Venugopal Sampathkumar)1. Solar PV value chain

a. Polysiliconi. 5 to 6 companies in this segment and none are from India

ii. These require highly sophisticated technology and capital and scaleiii. These segments are not suitable for low capital investors

b. Cellsi. Investment is not very high, but requires investment in R&D and also scale is

highii. It is not suitable for small and medium business

c. Modulesi. Less capital intensive and less technological requirement.

ii. More competitioniii. China is a major competition due to flexible debt, but now many of these

companies have gone bankrupt.iv. It is a place to enter the market – start own company, but may not be

economical or become a reseller for an established company which is more economical.

d. Invertersi. These are the brains of the solar systems.

ii. Requires highly sophisticated technology.iii. This is also not suitable for small and medium business.

e. Mounting Structuresi. Mounting structures depends upon geographical areas.

ii. Capital investment is not highiii. Designing mounting is more valuediv. There are many openings in this sector

f. Monitoring Systemsi. Has high scope, and requires less capital but has very high competition.

g. Balance of Systemsi. Cables, junction boxes etc.

ii. High competition and have to compete with electrical giantsiii. Have to have good strategy to enter as scope is good

h. EPC: Utility scale / Rooftop or Off-gridi. Scale is different for both utility scale and rooftop scale

ii. Investment varies based on scaleiii. Rooftop has big potential but requires marketingiv. There is scope for both utility scale and rooftops.

i. Utility Scale Plant Developmenti. Selling power to private or government sectors

ii. High capital is required.iii. Depends upon financial planningiv. Not advisable for small and medium scale businesses

j. Solar Productsi. Selling of products with usefulness for its entire life cycle

ii. Has good potential as it does not have big players.2. Solar Value chain can be further divided into smaller parts where small businesses can enter

a. O & Mb. Designc. Project Managementd. Construction

3. Testimonial by Sridhar4. Issues in Solar Industry

a. Subsidies – based on government policiesb. Volatility

Session 4 (L&T) – Diesel to Solar1. Study was carried out on performance and economics of solar vs. diesel.2. Diesel generators produce power at a rate of Rs.17 to Rs.22 per unit.3. Solar investment has reduced from Rs.20 crores per MW to about Rs.8 crores per MW.4. Solar may achieve grid parity in couple of years.5. Hybrid systems and Micro-grid systems are discussed6. Issues with Solar – Diesel Hybrid Systems

a. Instability in system as solar power is intermittent.b. DG should be run at 50 to 70% load, but should never fall below 30%.

7. Control System monitors and controls the issues mentioned above.8. Benefits of Solar-diesel hybrids

a. Peak demand restriction savingsb. Load shedding is preventedc. Lesser operating cost compared to use of diesel only

9. With battery storage, the quality of power and fluctuations is reduced.10. Financial analysis must be done to determine IRR and see if it is profitable and feasible.11. When latitude is less than 10°, it is better to have them aligned in east west axis rather than

having them face true south.