1 MW Narmada Canal Solar Power Plant

I don't look nearly as dashing as Mr. Modi, but I did wear my Modi kurta! They also didn't give me a red stage to stand on...

The 1 MW Narmada Canal solar power plant was constructed by SunEdison for the Gujarat State Electricity Corporation Ltd (GSECL). The Sardar Sarovar Narmada Nigam Ltd. (SSNNL) owns the canal and the GSECL leases the canal. Since both companies are state owned, it was easy to arrange the lease, I was told. 

The plant produces about 1.5 million kWh per year and frees up 5 acres of land for productive use. The PV plant also provides power to local farmers who live along the canal, which reduces transmission losses that are around 30% in India. 

The 750 m long power plant is broken up into 8 blocks of 125 kW each. Each block has 14 rows of panels and each row has 32 panels. Here you can see the individual rows. Each row is made up of a 2 x 16 rectangle of panels. 

Each row feeds into a junction box, which the orange wires lead to on the right.  

The water from the canal cools the modules which increases their efficiency. It was a lot cooler underneath the system than above it! The system also dramatically reduces the evaporation of water as well as reduces the growth of algae and other plants which can clog the canal. 

If you compare this picture, which shows the exposed canal at the far end of the plant,  to the one above you can see the dramatic difference in the amount of plant life. The brown grass also indicates that there hasn't been much water in the canal lately.

The biggest problem I observed with the system was erosion. You can see the exposed foundation of one of the rows in the picture above. The canal is designed to carry water and during the monsoons the water from the surroundings farms runs to the canal eroding the dirt sides. Having the sides of the canal only partially cemented was a big design flaw that should be addressed in future canal PV systems. 

A junction box with an eroded foundation is shown above. Building a PV plant on an existing canal without fully cemented sides does present some potential issues. The Gujarat State Electricity Corporation Ltd. (GSECL) leases the canal from the Sardar Sarovar Narmada Nigam Ltd (SSNNL), which owns the canal. Since the site owner is different from the system owner, who pays for fully cementing the sides may be an issue.  

With the current plant, who pays for the maintenance may also be an issue. SSNNL may usually waited longer to rebuild the sides of the canal, but the GSECL may need them to rebuild the sides more often so that the junction boxes don't float away! Since both entities are state-owned, they will likely figure out some way to sort it out, but who bears the cost of maintaining the canal should be specified in the lease contract for future canal PV systems.

SunEdison also build a small 10 kW system on land next to the canal system to monitor the difference it efficiencies between the land and canal systems. I think the 10 kW system also provides power to the inverter room which is the orange building in the background, but I am not certain about this.

Despite the erosion challenges, it is truly an innovative system. It is necessary for the first mover to act and encounter problems so that future plants can learn from their mistakes. 

Gujarat has plans to build a further 10 MW of PV canal plants along the Narmada canal, so lets hope they build fully cemented sides to avoid the erosion issue. 

The Narmada main canal runs 450 km with 19,000 km of branch canals. Only utilizing 10% of the canals would be 2200 MW! There is great scope for expanding this cool system design throughout India and the rest of the world.

The state water project (SWP) in California, which brings water from the San Joaquin delta to southern California, is the largest consumer of electricity in California. It consumes a whopping 5 billion kWh (TWh) per year. The SWP consists of over 1,000 km of open canals and pipelines. [1] If we assume that 3/4 of the SWP is open canals (not sure how accurate that assumption is) that leaves 750 km. The Narmada canal system produces 1.5 million kWh in roughly 1 km, so that means a similar system atop the SWP could produce about 1 billion kWh's per year. Surprisingly that is only 20% of the total energy consumption, but is better than nothing!

The Narmada canal is all gravity flow, so it doesn't consume any electricity.

Seeing the canal solar power plant was a high point of my time in India. I was delighted to see such a innovative! I hope more countries around the world adopt this idea, only with fully cemented sides.