Too implusive about solar impulse

Okay, I get it.  You can circumvent around the globe (albeit with many halts) using solar energy.  Super wide wing span and room for just two with no air conditioning and pressurization; you’ve really made it a point that it is a definitely NOT an alternative to our jets.  Then what is the idea.

We humans are spoiled with our need to travel and we will only have more pressing needs as we move on.  With limited fossil fuels reserves, we’ll see air travel becoming more and more expensive.  Think about the time when there is no jet fuel available to pump into jumbo jets large fuel tanks.   It is definitely not a very pretty scene.

This is the place where, I predict, the pricing will increase at triple digits compounded year-on-year.  When this happens, the price of traveling will be so expensive that only the elite few can fly economy class.  Generally, it’ll become rare – if not impossible – to fly and the most of the planes will be grounded.

Here comes the SUN.

Like always, sun comes to the rescue.  My question is, is it powerful enough to replace conventional jet engines?

I have many reasons to believe that it’ll not.

1.Theoratical maximum efficiency of PV modules is about 45%.  Meaning, if the current cells with 20% eff were replaced with the hgihest efficient cells, you will have about twice the power.  Meaning, twice the total energy.

2.Batteries still remain a main problem.  Solar impulse is doing journey mainly during day time as it has very limited storage.  Even if we move to the highest possible efficient storage, the weight will still remain concern.

3. The current design is a very basic and frankly very ambitious design suited only for the iron heart travelers.  It’ll need to have all the frills that a normal passenger needs in order to make it travellable.  If a person who is going to pay through his skin to air travel, he will expect minimum level of comfort.

To sum it up, air travel days are limited.   My suggestion, go out and take a world tour!

So, whats the substitute.  I think high speed land travel is a definite.  We’ll see high speed rail links criss cross lands and oceans.  That is a definite possibility.




After all the debate, we go back to where we started, BATTERIES!

Dear All,

The classic debate within solar industry has been over the fact that solar panels generate energy during day time and therefore cannot inherently become primary energy source.  Grid as virtual storage of excess energy is fast becoming a ‘castle in the air’  as solar energy is gaining a larger and larger share within the energy mix pie and therefore cannot be neglected due to its growing size and significance. Our blinding and growing fascination with solar energy has lead us into striving harder in finding ways in which this drawback can be circumvented.

A lot of resources have been dedicated into finding ways by which this ‘excess’ energy from PV systems can be trapped and released on later time in order to utilize PV systems optimally.  One system that is coming out, surprisingly, is the conventional battery banks.  Just today, California has asked all utilities to incorporate battery bank systems within its network to over come the dichotomy of haves and have-nots of PV energy.  A so called bridge between two phases in essence – is being contrived using battery bank.

Being an eternal averse of batteries as I am, I strongly urge the authorities to consider wider options than just throwing something unreasonable, just because you can.  I need to divulge into the detrimental qualities of batteries to project the ruinous nature of the batteries.  It is really important however that a clear thought is given to the idea of storage.

A problem we are talking about is so called valley being created by PV system in the primary energy demand.  Instead of ‘clipping’ the peak, PV now creates a valley during the day time which leads to extra pressure on the primary sources of energy during early morning hours and more importantly in the evenings, when people – after having worked an entire day – go back home and switch on their air conditioners and television sets. This is called secondary peaks.  One major peak is disappearing and two smaller peaks are being created.

A classic example again of operations – you optimize a bottle neck and another bottle neck emerges.  What do you do?  You move on to optimize the new bottleneck and keep doing so until you have no bottle necks, which essentially is in perpetuity.

In PV industry, how is this being addressed?  The so called new bottle neck is being brushed under the run by evening it out as if it never existed – by creating battery banks to even out the bottle neck.  Here is why the idea is grossly wrong.  Operations management does not propose to even out the bottlenecks as a flat playing ground.  It instead says that you need to go behind the secondary bottle necks instead of evening them out.  Here we are doing the opposite.

There is another problem with this strategy.  Lets assume at this time, we have excess energy from PV system of 10MWhr, and you create this storage to spread this excess energy out.  This by no means is the end of it.  With the rate at which PV installations are growing, we’ll have a need of 100MWhr storage within 2 years.  So, are we going to constantly grow the storage until we generate all our energy during day time and store all of our needs of night in the batteries.  Remember, this becomes even messy when you include the fact the our energy consumption grows as our life style grows.  So, the battery bank will have to be added constantly.  Hmmm.

So, if not leveling out, what is the way out.  I say, let us remain classical in our approach.  Let us kick in our standby generators whenever required.  I strongly believe (and have some numbers to back it up) that this will only be more economical than introducing storage in batteries.  Well, it will costs us more to generate during night time.  So what? Let us charge the consumers more for using electricity at this time.

Storage is NOT the way forward.  Investing in finding good mix of renewable energies keeping the conventional sources as underlying means will probably guide us in right direction.  Say no to batteries.

Batteries are bad, say no to batteries

We are going back in our evolution by choosing to use batteries as storage.


Peel N Stick PV cells – Infinite possibilities start here!

Okay, this is really getting interesting.  A month ago there was an announcement by a Japanese guys that they have cracked into fabric based PV cells.  Now, we have this hugely interesting news from guys at NREL and Standford that they’ve gotten hold of technology to make PV cells in form of stickers.

So, whats next, paint based cells.  Oh wait, we already have this, don’t we?

Anyhow, let us limit our discussion on the peel-N-Stick cells.  When you ask me to compare the two technologies, fabric based cells vs. sticker types, sticker types is definitely a winner, hands down!   I am sure you guys are smart enough to decipher my claim!

The real challenge will be on applications, easy and adaptability of the same to the existing gadgets.  Just like computer market, where the real winners have mainly come from application developers (Microsoft, Facebook, and likes) vis-a-vis computer manufacturers like IBMs and AMDs – the real winners in this field will  also be those that come with novel ideas using this technology rather then the developing the technology itself – which will be slow but sure process.

So, with this super technology, it’ll come down to how well the applications are developed rather then how efficient the cells work or how quickly they stick to the substrate.   Deep pocketed industries will invest into perfecting this technology but the real genius would be into thinking out applications of this stuff.  Just as the developers have claimed, one such applications will be using them on gadgets like cells phones (provided cells phones still exist by the time this stuff comes out commercially).

Here is one such though.  How about using this pee-N-Stick solar cells to cover the batteries (consumer / industrial / space – you name it) to both insulate them from hot direct sun light while providing some kind electric current by which – using thermoelectric effect – surface of these batteries is kept in controlled temperature.  This unit will provide cold surface in hot climates and heat in cold climates.  Energy for this will come from the stickers itself.   Now, this is something to ponder.

I am looking for patent lawyer!!!

Solar Fabric – Gimme one!

Solar fabric unveiled by a Japanese Company

Okay, so now its official.  It is definitely feasible to make shirts and trousers and sun shades that generate electricity.  Japanese private firm has hit a home run by releasing a fabric with PV cells embedded in it.

If it is possible to commercialize it – after all the various improvements that the firm is claiming to introduce – here are my thoughts on the range of different applications once could possibly see coming in from this material.

But, first, let us get a stock of reality check on it.  The product is in infancy stage of development.  The company says that there are still some challenges including durability of the fabric, isolation of electric conductors and proper weather proofing of the circuit.   With all these ‘extra’ layers of protection coming in, this product is definitely not going to be ‘soft and silky’ to be worn as shirts and skirts.  So, I foresee this product requiring a lot of iterations of development before we see it coming even close to entering textile industry.

So, let us concentrate on commercial fabric industry.  Starting with blinds in offices.  Blinds are, a good possible use of this fabric.  But, while it sounds good, there are generally some major drawbacks of using them as blinds.  Blinds are not always kept in closed position meaning even though you have invested into having these PV powered blinds, you would not always get the maximum energy yield from them.

Tents: That surely is very promising field for this technology.  Tents are used in places where the power is scare – if available.  With modern life and digital age, people find need for energy even when they are camping, hiking or being ‘supposedly seclude’.  This new lifestyle and resulting power needs makes good business case of having fabric used in tents produce power that could possibly be stored.  Add to this, general availability of unobstructed sun light at places where the tents are generally pitched.

Car ports: This field has been trying really hard to use conventional PV modules within its designs.  Even though some of the best designs have been used previously to ‘attract’ potential large clients, this has not necessarily taken off in big way.  Some constraints include need for specially designed super structure for mounting PV modules.  Even after putting the system up, you are definitely not going to get a complete water proof shade for your fine cars.   The over all cost of ownership is much higher than if you were to use conventional fabric shade that meets all your need at much lower price and having all those PV modules mounted on the roof of your house.  With all those serious issues, a fabric based PV system will definitely fly.  Not only it’d need smaller structure, but it’ll also do all those basic things that a traditional fabric based shade are expected to do.

So, there is a definite market for this product.  My verdict, Go for it, Mr. Japanese!  We are waiting to hear more from you.


RTA bus shelters ACs by Solar – Not a good idea

Dear All,

It was recently reported in the local news paper that the local transport agency of Dubai (RTA) is considering using solar energy for running air conditioners within the bus shelters.  Here is the reason why I think it is not a good idea

1. Economics: The average size of each air-conditioner is about 5KW.  Let us say that it is going to run for 12 hrs/day; so the total energy required per day is 60KWhr.  To have solar power (off grid – it seems like this is what they are referring to in the article), the initial set up cost adds up to about $150,000.00 (conservatively).  Compare this to the prevailing cost of electricity in Dubai of $0.07 per KWhr.  Savings per day is 12 x 5 x 0.07 = $4.20.  Breakeven point for the initial investment is $150,000 / $4.2 = 35,700 days or 97 years!  Anybody needs a calculator?

2.  Feasibility: In order to deploy a system of this kind, you would need installation of about 14KWp.   Total area required for installing a system of this size, you are looking at 140m2.  Assuming typical width of footpath next to the shelter where the installation is done to be of 5m, it’ll need 70 meter (unobstructed) footpath for doing the installation.  This is close to a typical city block! Unless, RTA plans to elevate and provide shading to the pedestrians using PV modules, no reasonable solution is possible to put these modules.  Add to this complexity in finding unobstructed locations for mounting PV modules within the city with high rise buildings.

Here is what is possible, however.

It is known that a direct air ventilation creates a feeling of temperature about 20 degrees lower than ambient.  If fans could be mounted inside the shelter along with vents (all DC rated highly efficient motors), then you could essentially provide relief to the passengers from scorching heat outside.  PV modules should only be used in places where grid supply is not available.  The shelter roof could be used for mounting PV modules for this load.Can solar power be used for these shelters?

Myth behind Solar Street Lights

Hello visitors and bloggers!

This is the first official blog of Apex Power Concepts!  You are welcome to leave a comment(s) and share your opinion about the topic being discussed.

The first article is about Solar Street Lights – more specifically the myth that surrounds solar street lights!

Solar street lights essentially street lights powered by batteries that get charged by solar PV modules (sun energy to electricity).  All the components within the system are mounted on a single pole.  The main components within the system include PV modules, batteries, charge controllers and switchgear.

Now, to the myth.  According to some proponents of solar street lighting systems, all the solar street lighting systems are a. good way to save money and b. environmentally green solutions.

Here is why both the above claims are plain flat false.  Let us start with the first claim that solar street lighting system is viable.   Lets take an example of a typical installation that requires solar street lighting system for 10Km of road.   Typical installation involves using 120W LED lamp on 10m pole, with pole to pole distance of 40m.  With this arrangement, we are looking at total 250 street lights. This assures a good consistent light spread of about 15 Lux.

If normal AC lamps powered by grid are used, the extra cost involves cabling and other related civil works (cost about $300,000) and annual cost of running the lamps ($9,000 per year or $36 per year- $0.07 per KWhr – current rate of electricity in the UAE).   Typical installed cost of each pole – $1,250.00.  Therefore, total costs  per lamp adds up to $2,550 + $36 per annum.

Now, let us look at solar powered street lights.  The installed cost of each lamp falls around $2,000.00 (very conservatively).  Now, let us add maintenance (cleaning of modules) at $200 per pole per year, changing batteries every 3 years @ $500 which is essentially $133 per year.  Therefore, total cost of solar street lights is $2,000 + $333 per year.

You don’t need excel spreadsheet to comprehend the different in cost of ownership.

Moving on to the second part of the myth that solar street lights are good way to save the environment.  Here I call you attention to the following link

USA, that promotes recycling through programs like free collection of bad batteries at various collection points spread across the country, gets the collection of old batteries as been at dismally low level of 10%!

What happens to the balance of batteries?

Again, may I bring your attention to the following page

I quote from the above link

Some lead compounds are extremely toxic. Long-term exposure to even tiny amounts of these compounds can cause brain and kidney damage, hearing impairment, and learning problems in children

And more..

While lead recycling is a well-established industry, more than 40,000 metric tons (39,000 long tons; 44,000 short tons) ends up in landfills every year. According to the federal Toxic Release Inventory, another 70,000 metric tons (69,000 long tons; 77,000 short tons) are released in the lead mining and manufacturing process

I don’t see any green part here!  90% of the batteries typically end up in the most destructive way into landfills.