In Search of Cogenra Solar – Part 2

[Mountain View, California USA]

More information on the SWC installation and the Cogenra Solar cogeneration system.

From Cogenra Solar

The Monday response after I posted In Search of Cogenra Solar was swift. Antenna Group commented for their client, Cogenra Solar, to clarify the Sonoma Wine Company (SWC) solar cogeneration system status:

Ed, the system is fully functional, but was shut down for the weekend since the remote performance monitoring and alerts system, planned as a part of every Cogenra installation, have not yet been connected. Cogenra expects the system to remain in continuous operation once the remote monitoring system is online.

Towards the end of last week, Sonoma Wine Company Director of Business Development Natasha Granoff said:

We are very pleased and satisfied with the performance of the Cogenra Sunbase™ modules that have been delivering both heat and power helping us reduce our natural gas and electrical needs. We do not yet have detailed monitoring information on output — we expect the reporting system to be enabled in the coming weeks.

My SWC site investigation also garnered an interview with Cogenra Solar at their Mountain View headquarters.

During a frank discussion with Cogenra Solar CEO Dr. Gilad Almogy and CMO, VP of Corporate Development, Mr. Preston Roper, I learned how Cogenra went to great lengths to ensure the SWC solar system was fully operational for the commissioning celebration. Cogenra Solar considered the milestone a serious event in stark contrast to a critical comment from a possible stakeholder. A commemorative wine was bottled Tuesday of the same week while the solar cogeneration system was in full operation so the Made with Renewable Energy marked wine label was 100% accurate. While having the Cogenra system generate clean renewable electricity and hot water for the special wine bottling was easy, the wine label approval process became the gating item.

Next, Cogenra wanted to address each of my questions from the Blog and correspondence.

First, I asked about how the system captured heat and whether there was a mechanism besides cooling the PV (Photovoltaic) modules. I had developed one good theory and a few bad ones I almost blogged about. Cogenra responded that module cooling was the primary mechanism relying on operation 35 °C above ambient and citing solar PV module operating temperatures of 70 °C were common in a city like Phoenix, Arizona. Low-Concentration PhotoVoltaic System, SunPower Style, about a comparable technology, corroborates the assertion with preliminary thermal data observing the cells operating “on average between 25°C and 40°C above ambient temperatures” depending on the wind conditions.

I observed the Cogenra Solar cogeneration solution was potentially not scalable to a customer’s electricity and heat requirements in a greater than one to four ratio based on capacity (“50 kiloWatts of electricity, and the equivalent of 222 kilowatts of thermal energy”). Cogenra agreed the system was constrained either by a customer’s annual electricity or heat requirements but stated heat was usually the first to max out. Cogenra believes the ratio of heat to electricity production is well suited to their primary target markets of the food and pharmaceutical industries as well as community solar. I was pleased to hear Cogenra mention complementary PV (photovoltaic) solar can be added to a customer specific installation to address their total electricity requirements.

Cogenra’s Hybrid Solar: Mirrors, Silicon & Heat” by Ucilia Wang was the first to mention Cogenra’s system water temperatures and skewing system operation to electricity or heat demand:

Cogenra plans to explore ways to automate the system so that it can, say, focus on generating more electricity and less heat at different times during the day when electricity rates and demand are high, said Almogy.

I had to read Cogenra’s approved California Public Utilities Commission (CPUC) grant project description a few times to confirm this was not for the SWC installation itself but instead for:

9. Improved manufacturing and innovative business models to accelerate commercialization in California of hybrid concentrating photovoltaic/thermal tri-generation (CPV/T-3G) technology by Cogenra Solar. Cogenra Solar (formerly known as Skywatch Energy, Inc.) has developed, prototyped and validated the technical performance of an innovative concentrating photovoltaic/thermal co-generation technology and will conduct an 80 kW demonstration at the Sonoma Wine Company. For this project, the field performance of the system will be measured and used to refine economic and financing models and optimization over multiple tariff structures. This project will also look at modifying the co-generation system so that it can support tri-generation of electricity, heating and cooling, expanding the market to include commercial sites that require cooling and lower amounts of hot water. Additionally, Cogenra Solar will modify the system to provide energy storage for use during peak demand and coordination with Pacific Gas and Electric Company on grid integration. The project will receive $1,467,125 in CSI RD&D grant funding with a matching fund of $2,774,157.

Cogenra emphasized their primary service offering will be the HPPA or Heat and Power Purchase Agreement. As with PV Power Purchase Agreements, there are no upfront investment costs to HPPA customers and immediate electricity and natural gas utility savings. When I asked if it was difficult to model site specific electricity and heat generation and demand, CEO Almogy assured me Cogenra Solar had developed an exhaustive model of the SWC installation to insure attractive project investment returns. For customers displacing expensive propane instead of natural gas, the energy savings are even greater. Dr. Almogy noted a few customers with tax equity would still prefer outright purchases of the solar cogeneration systems.

Cogenra addressed my question about closed loop CPV (Concentrating PhotoVoltaic) operation noting a simple dry chiller would cool the glycol mixture for continuous electricity production minus a small parasitic power demand. In fact, Cogenra Solar showed me prototype systems in Mountain View using this exact setup for testing since their leased building did not allow for hot water integration. In the same quick tour of Cogenra’s proving ground, I saw the flat glass mirrors of what I have dubbed the Parabolic Linear Fresnel Reflectors (PLFR) close up and inquired about the metal pipes protruding from the front of the receivers. The “dog ears” are used to interconnect the glycol mixture between adjacent modules while providing strain relief to guarantee twenty plus year system operation.

I believe the Heat and Power Purchase Agreement will be a lasting contribution of Cogenra Solar though the company will now need to prove they can capitalize on their HPPA business model and contractual innovation as a path to solar cogeneration success.

The above photo is from my efforts to investigate Cogenra Solar the weekend before the SWC installation commissioning celebration.

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