Concentrated Photovoltaic (CPV)- CPV solar uses mirrors or Fresnel lenses to focus the sun to a small area of photo voltaic (PV) solar cells. Mirrors and Fresnel lenses are less expensive per square meter than PV cells. By reducing the amount of PV surface area needed (1/500-1/1000 of traditional PV), solar can be manufactured at a significantly less expensive price.
Like traditional PV solar cells, CPV solar cells are wired together in series—meaning, the cells are connected in a single line from beginning to end. The electrical current runs through each cell in line like water in a pipe.
In this configuration, however, a solar panel’s performance is limited to the worst performing cell in the line. Even when all other cells in line are working at 100%, if one cell is only working at 50%, the entire output will be at 50%. Further, if one cell in line is entirely shaded, even though all other cells might be exposed to 100% sunlight, the output of the entire PV panel will be 0%. This issue is exponentially worse in CPV.
As mentioned above, CPV is the most cost effective configuration of PV solar. Instead of expensive PV cells covering massive square-footage, lower-cost mirrors or even inexpensive plastic can be used to focus the sunlight through Fresnel technology onto one PV cell, or a small array of PV cells. This focusing process can reduce the PV area by as much as 1000 times.
Unfortunately, while this lowers the cost, it also increases the chance for power loss and instability exponentially. Vibration, motion tolerances, micro delays in turning mechanisms,
among other things, will cause the focal point to drift off from one or more of the receiver’s PV cells from time to time. The focal point moving off of one PV cell, even momentarily, can drop power production from 100% to 0% in milliseconds.
The promise of low-cost, CPV is high. Therefore, companies have yet to give up on ways to solve this critical problem. One
solution currently being developed is a kaleidoscope diffuser to optically spread out the focal point evenly across the receiver’s PV cells. This design is extremely complex and interjects additional efficiency losses, not to mention added maintenance.
In a very simple and inexpensive way, the DVC circuit resolves this issue. Each, individual PV cell can be switched parallel into its own cap. When the caps are discharged, they switch off input from the PV cell and switch to output in series. For continuous electrical flow, the PV cell would charge a second cap in parallel while the first is discharging in series. By utilizing the DVC circuit, each PV cell’s performance acts independent others at all times. If the focal point misses one PV cell, it doesn’t effect the power output of any of the other PV cells as it otherwise would.
Potovoltaic (PV) Solar and Smart Grid- As more and more solar PV panels hook to the grid, power companies are finding it difficult to mitigate the overall effects of instantaneous power drops and spikes caused by PV solar cells’ reaction to cloud cover. Within milliseconds, a 10 MW plant can drop to 1 MW or less from a drifting cloud passing over the sun.
When too many PV farms are tied into the same grid, they become a driving force. When the grid’s balance of power begins to lean toward PV farms, their instantaneous stops and starts of electrical current can wreak havoc on generators driven by traditional power plants on the same grid. The kinetic force when a generator shaft turning a rotor at 1,800 rpm comes to an instantaneous stop over and over again significantly shortens its lifespan and creates unpredictable brownouts and blackouts to grid systems.
The DVC can create a buffer to level out these power on and off spikes. In essence the DVC circuit becomes a smart grid where the voltage controller can act as a barrier between the grid and power generators. Whole grids can be knocked out by surges, leaving potentially millions of people without power. IAUS’s technology is capable of controlling a safe-zone by constantly analyzing the grid environment and keeping an added layer of separation between grids, end-users, and power generating facilities.
Dynamic Voltage Controller (DVC)
DVC Prototype Videos