SolarEdge system design Insights

Solar PV System Design:

As you have been reading my blog, you will see that SolarEdge is the only Inverter/Optimizer/PV harvesting system that makes any sense at this current time.  When ever you have more than 16 or so panels on an inverter, you should always use two strings.  I have come up with 4 good reasons for doing so.

4 Reasons to use 2 Strings per Inverter

The min number of panels per string is 8 and the maximum is  around 28 (25 SE).

1.0 By running two strings you reduce your power losses in your wires by 50%.  That could save you as high as $1500 over 20 years.

2.0  Having 2- 10 string panels verse 1 20 panels on a string will allow you to easily expand your system without much difficulty.  A 10 kW system would still be limited by the inverters.  That is how every other power plant is designed.  You can not track the sun's path, but you can increase your gross harvesting and help slow the CO2 growth. 

3.0  I was recently informed that the optimizer can fail and take out the circuit.  This would be a rare event but two strings will reduce your cost to find the faulted optimizer, improving maintainability. Optimizers when they rarely fail, normally fail without taking out the circuit.  I don't know how they are wired but an internal meltdown would most likely take the string down.  Don't worry about this but design the maintainability by using two strings.

4.0  Having two strings, the Inverter just works better at controlling the power curve.  A very good reason in it self for having two strings.  SolarEdge recommend two strings.

The only down side is if your panels are covered with so much snow that you will not turn on.  We clean our panels in the winter so that the system keeps working all year so that is not a problem for us.

Your installer may try to tell you that two strings are not needed.  You don't have enough experience to tell them other wise.  They just want to save the cost of wire and labor.  Put 2 strings per Inverter in you Engineering Specification for the above reasons for maintainability and overall system performance.  Makes sure that it is part of your contract in writing before you sign the contract.  If people want, I can post my Engineering Specification.

One Smart Designed Inverter

If you have enough solar panels to exceed the rated output of the Inverter that is a good thing.  The Inverter just turns the panels off that it doesn't need until it needs the power.  It does NOT dump the power to a resister and the Inverters always run cool, even in the summer on a hot day. It does another thing also.  The range of the DC voltage is 350 to 500 V.  When it detects that it is operating at maximum the Inverter increases the DC voltage from around 365 V to under 450 V.  The reason it does this is to reduce the amount of current flow, not power coming into the Inverter.  When you shut off the system, you still get 1 V per panel so the system is safe for Firefighters.

There is one very rich guy in Windsor who runs 25 microfit programs.  A few years back, he removed all of his systems and installed solaredge with some 40-50 panels per system.  He harvests the maximum that he can and gets paid the 80.2 cents per kW and not the current under 39 cents.  He would earn around $400,000 per year estimated or 20 MW per system per year.

I hope that these insights will assist you in getting the maximum out of your system.  The world is in really bad shape due to high CO2 levels, see my other blog.  

Go Solar.

Is CO2 Really a Problem?

Acidification of our Oceans:

Hi again.  I would like to share some information that recently became available to me.  One of my areas of expertise is Industrial Water Treatment.  I watched in horror a program about acidification of our Oceans.  I believe the area in question are pockets of ocean along the west coast of North American and other coastal areas in other countries.  These areas are not receiving the full mixing of ocean currents.

I keep hearing people say, we don't need solar or wind power.  Nothing could be farther than the truth.  Some people talk about a tipping point.  That is a point when you exceed, you can not go back and all hell starts to happen.  I believe that we have already passed that tipping point on the West Coast.

CO2 or rather 30-40% of it is absorbed by the Oceans.  We thought that that was a good thing.  Ocean pH. is normally 81.-8.2.  It has a bicarbonate alkalinity of about 120-150 ppm at this pH.  C02 forms carbonic acid  when dissolved in the water.  Every ppm of CO2 removes two carbonate atoms.

A oyster hatchery experienced 100% die off of their crop about 3 years ago.  They were totally puzzled until someone said check the pH of the sea water and they found it to be 7.6.  That is about 60 ppm of alkalinity.  Below a pH of 7.8 corals will not grow.  I used to have a salt water reef aquarium and sold products to raise the pH and to help people grow their corals.  These hatcheries are seeing a 50% drop in harvesting or  survival of shell fish in the Ocean due to this drop in pH from a normal level of 92%.  As it gets worse we will see a global decrease in the fish and shell fish populations. 70% or more people depend on the oceans for food.  The low pH effect the low level plankton survival in the oceans.  WOW or rather OH SH..T

FYI a pH of 4 is equal to 0 ppm of alkalinity.

We have already passed the tipping point.  It wasn't 400 ppm CO2 but much lower point.  China keeps burning coal like crazy along with the USA.  300 ppm could have been the tipping point for the oceans.

Simply put, the world is in big, big trouble.  We need more solar and wind generation or non-carbon based energy production.

Our crazy Federal Government is talking about buying Carbon credits.  Take that money and seed crushed limestone on the ocean where the pH is low.  You would most likely not see much happen but it would be far better than giving or buying stupid carbon credits.  This is an enormous problem.  Even squid need pH about 7.8 to form a small Calcium Carbonate bone the size of a grain of rice to help them keep their balance.  Below a pH of 7.8 and it does not form normally.  In the ocean you are either squid food or squid.  Many larger predators eat the squid.  All that will be left will be the jelly fish.

Note: CaOH would be the best but it is produced by driving the CO2 from limestone, just like how cement is made.  Thus all you would do by using this is to add more CO2 to the atmosphere.  By the way, with all of the cement that China is using, they have an enormous carbon footprint from cars, coal burning electric plants and the huge industrial growth of concrete buildings never mind the huge methane foot print of 1.3 billion people.

Conclusion:

I personally along with my other experts never thought that this would be happening now.  Lower your carbon foot print.  If you can, put solar panels on your roof.  We are now in a very, very bad point in time.  You can  add that I did not speak about increasing the global temperature.  This is the other problem.  Wait until the north starts to warm up and all of the methane gas is released which is even worst than CO2 at keeping the heat in.  This will be a run away cycle of destruction.  I don't see many people listening or even caring.

If you think after reading this that it sounds bad.  In reality is it is 1000 time worst than you may be thinking.  Be prepared for massive starvation across the planet as the rivers dry up in India and China runs out of food.  Both of these two countries will have 2 billion people each in another 10 years.