Sunday, August 10, 2014

Failed Wind Turbine Installation

I have a very simple question. Do you place a PV panel in the shade to produce electricity? Do you place a hot water collector in the shade to produce hot water? Obviously NOT, however I witnessed an installation of a wind turbine installed exactly where there is no or very little wind!
I have noticed this installation for over a year now but it seems that the owners are happy with it... The turbine does spin but I guess that's it more of a roof ornament than an operational piece of an engineering.

From the looks of it, the turbine is a 'Proven Wind Turbine'. These turbines are manufactured (or better used to be) in Scotland. They used to be good/solid turbines built like a tank back in the 90s however it seems that the company went bust a couple of years ago.

The pictures below clearly show the wind turbine installation on top of a roof right next to tall buildings. The site is already not ideal because it's at the bottom of a hill however the turbine installation (especially the tower height) continues to make things worse.

A small wind turbine (500W - 1KW) should be installed at least 30 feet above all buildings with a clear radius of at least 500 feet. In Malta these guidelines are not always possible to adhere to due to our zoning restrictions and overly populated/built country however at least, the height should be maintained. The taller the tower the better, because the best and consistent wind is found at high altitudes where there is very little turbulence.

The picture below clearly shows buildings at the same height of the turbine on the right!

Why did I bother to write about this turbine? Simply because this turbine is installed at MCAST in Paola where most probably, studies are being conducted to determine wind power feasibility!!!!

Wednesday, August 6, 2014

The Electric Experience

This post is dedicated to my experience driving an electric car for eight weeks.

Back in 2012, I applied to be selected as a volunteer to experience driving an electric car. Funded by the EU, I applied for the Demo EV project (Demonstration of the Feasibility of Electric Vehicles towards Climate Change Mitigation) Project no. LIFE10/ENV/MT/088)

25th July 2014
Go Clean, Go Silent, Go Electric
Finally I was handed over my chosen car. I opted for the MIEV. Some basic features of this car;
  • Fully Electric.
  • Expected range on a full charge - 160Km
  • 47KW Power Output.
  • 180 Nm Torque.
  • Battery Type - Lithium Ion
  • Battery Voltage - 330v
  • 16KW Battery Pack.
There is a lot of scepticism about driving an electric car and the best way to overcome them is by reporting back from a hands on / direct experience. Although I'm biased towards the use of the electric car and it's advantages, I will be faithful and report back exactly the car's performance.

Week 1 (25th July --> 31st July)
Distance Travelled: 177Km
Number of Charges: 2 (Home & Charging Post (CP))
Air Conditioner: Not used.

I performed my first charge at home to measure exactly the power requirements. Using a power meter, I have the following data :-

Voltage: 248.33v
Current Sourced: 12.58amps
Power Factor: 9
Power: 3124 Watts.
Peak Power: 3142.Watts

Charge Capacity Before: 31%
Charge Capacity After: 100%

Total Power used: 11.3KW
Unit Cost per KW: Euro 0.16c
* I'm basing the KW cost on last year's rates simply because I haven't yet received a bill for this year. I'll revise once I actually receive a bill from ARMS!
** I'm ignoring the fact that I have PV panels at home in which case the cost would have been much cheaper.
Total Cost for reaching full charge: Euro 1.81c

To charge to 100% from 31%, 11.3KW or Euro 1.81c were needed.
Therefore a full charge from 0% to 100%,  16.37KW or Euro2.62 will be needed.

And the most important question of all! How much does it cost to travel with the car? Well basing on my first 2 charges;

Distance Travelled: 157Km
Cost for travelling 157Km: Euro3.1312
That's 50.14Km per Euro.

Week 2 (1st Aug--> 8th Aug)
For my 2nd week, I have partially (66Km) switched on the AC as shown below.
Total cost for travelling 352Km is Euro7.25
That's 48.55Km per Euro, obviously slightly less than week 1 due to the AC use.

As the weeks go by, I'll be able to draw a much more accurate average and will also compare to my other two internal combustion (ic) cars.
I have charged a total of 4 times for these couple of weeks, i.e. an average of twice a week. I'm very conscious when it comes to battery state, (i.e. what's left in the tank) and therefore I almost always charge when I'm slightly below half full.

A common question I get asked is, how long does it take to charge?
Well it depends on several factors:
1) How much charge is needed, i.e. how much is left in the 'tank'
2) Fast or Normal Charge.

Option 2 is currently out of the question because I was not given the 'fast charge' cable and it actually needs a 3 phase supply. From the manual, it is claimed that in 30mins, the battery can reach an 80% charge.

Option 1 can be easily calculated.
The battery capacity is 16KW. Assuming that we're charging from a flat state (which will never be),
and the charger consumes 3.12KW (let's round down to 3KW), then 16/3 = 5.33 hours. I would therefore assume that 5.5 hours will be needed to reach a full charge.

Most people will find this timing a show stopper! 'Why wait 5 hours to charge when I can fill up in a couple of minutes at the gas station?' Well, an electric car needs also a change of mentality and planning. With an electric car you do not leave the battery to drain and then expect to charge up in a couple of minutes.
There are a number of good times when to charge. The most obvious is at night. While the body is charging up for the next day during sleep, the car can also be charged up for the next day to provide a day or two of driving. I also find it convenient to charge while at work. I spend 8+ hours at work not using the car, enough time to leave the car plugged into a Charging Pillar (CP).

Three very exited boys on board the 'electric'

Week 3 (9th Aug --> 15th Aug)
I'll be continuing to drive with both the AC ON and OFF to better reflect my normal driving conditions.

Week 5 (22nd August --> 29nd August)
5 weeks passed.

From the questions I'm normally asked, I've noticed that people are mostly concerned mostly about 2 things;

1) Charging times.
2) Battery warranty.

Charging Times. On average I spend from 1 to 2 hours (Winter traffic jams) behind the wheel each day. This leaves the remaining 22 hours when the car is idle parked somewhere doing nothing. This time can be easily utilised to recharge the car. I had calculated that in about 5.5 hours, you can recharge the car from 0% to 100%. Therefore there is ample time in a day to fully recharge the car (from flat) each day! Much more than anyone will need simply because to drain the car battery to 0%, you'll need to travel about 160Km. I therefore cannot understand why this question keeps coming up? It doesn't matter how long the car needs to recharge simple because there is ample time in a 24 hour day to recharge the car.
In my opinion, It's more of a matter of change of routine than anything else.

Battery Warranty. People are very concerned about the 5 years battery warranty. Well let's forget the EV and instead image that we're purchasing an LED TV, a home appliance or else for who installed a grid-tie PV system - the Inverter which carries a 5 year warranty. Are we concerned with the 5 years warranty? Not really I assume, so why is it that the warranty on the car battery is an issue. The warranty is just a guarantee. The warranty is NOT the lifetime expectation of what we're buying. It does not mean that after the warranty of whatever we're purchasing expires, the item becomes scrap, so what's different from an EV battery. I can't image buying a washing machine with 5 years warranty and I have to replace it after the warranty period!
On the other hand, I have to admit that batteries do not have a very good reputation among anyone. Everyone associates batteries with car  batteries which have a very short life. The EV battery is NOT a normal 12v cheap starting battery. The EV battery is a long-life complex Lithium Ion battery. Why complex? Complex because it's managed by a complicated battery charging/monitoring system and not a simple car alternator.
(Apart from the 12v starting batteries, there are also batteries with a better reputation and longer life such as deep cycle batteries and forklift batteries. If properly maintained, these batteries can last between 5 to 15 years, so what's different from an EV Lithium Ion battery?)
A good primer on EV batteries can be found here at Home Power. This website is dedicated to RE stuff.

KM travelled split by AC usage.

Totals for the past 5 weeks. For just 20Eur, I travelled 1009 KM.
With my 'normal' car, I'll spend 20Eur on diesel in just one week. This is were the financials will start making sense. At the end of my trial period, I'll be doing a full comparison with both a Petrol and Diesel car.

Recharge times. This number can be a bit misleading simply because I have recharge more than 2 times a week for a shorter duration, basically charging more when not using the car.

Week 8 (Last week)
8 weeks passed and it was time to hand back over my EV.
Km travelled split by week & AC usage.
Km travelled split by week only.
Total distance travelled and total cost to recharge.
As seen above, I did 1732Km in 8 weeks and needed Eur36 to charge. (always based on 1 unit = Eur0.16). This translates to 48Km per unit of electricity or 48Km per Eur0.16Eur.
Comparing to my other 2 cars;
A 14 year old diesel, I worked out that I can make 1Km for Eur0.12, while a 1 year old Petrol, I worked out that I can make 1Km for Eur0.10. On the other hand, the EV needs Eur0.02 per Km.
Therefore the EV works out to be 80% cheaper (fuel cost) when compared to the Petrol car.
I was very satisfied with my EV. I enjoyed every minute of it. I obviously loved it's low consumption, no noise and high torque. Will I go for an EV for my next car? Definitely YES!

Tuesday, August 5, 2014

New Batteries (Off Grid System)

Finally, the new forklift batteries for my off-grid system arrived. After 7 years of service from my old forklift battery set, it was time to replace them since the old batteries were showing signs of fatigue & started failing. I had already replaced 3 of my old cells and the overall reduced capacity was a clear sign that the batteries had reached their end of their service life.
A short history about my old battery set. They were not new at all but had been scrapped from a factory since they were removed from a fork lifter. A good friend (and neighbour) Mario who used to work there, suggested to me to take them in and give them a try. I selected the best 12 cells (out of 24) and kept the remaining good batteries as spare. Well, it was really a good decision to keep them since the 12+ cells which I salvaged gave me 7 years of service.

The new batteries I purchased are of the same time. These are:-

Brand: Fulmen Forklift Batteries
Voltage: 2.11v per cell
Amp Hour: 680AH
Storage Capacity: 2.11v x 680AH x 12(Cells) = 17217.6WH or 17.21KWH
                             At a max of 50% DOD, 8608WH or 8.60KWH of usable capacity.

Width: 20cm
Depth: 12cm
Height: 46cm
Weight: Very heavy ~ 30Kg each!

Below is a photo of the installed batteries inside my existing battery box. Note the additional wiring which I have prepared to tap and measure each individual cell voltage.
Every month, I perform a check on the batteries and besides reading the SG of all cells, I need to also check the individual cell voltages. From these two measurements I'll be able to decided when an Equalisation charge is needed.

And next to the battery box, The photo below is showing the fuse box and the battery desulpahtors. One of the desulpahtors is 24v connected to the new battery set while the other desulpahtor is connected to my 12v battery system.

The new battery monitoring system.  I installed a digital voltage meter across all the 12 cells. These voltmeters can measure a DC voltage from 0v to 10v with an accuracy of +-0.1%. The supply voltage is quite flexible 4v - 30v.

And below a photo of the cell voltages during an equalisation charge...

The picture below is displaying a set of 12 fuses which I built using the tracks of the vero-board as the fuse wire. Since I have a wire running from each battery cell going into the battery voltage box, I needed to independently fuse each battery cell just in case! Instead of purchasing 12 separate inline fuse holders and fuses, I opted for the vero board track which is rated for 5amps.
Below is the circuit diagram of the battery monitoring system. I used two separate power supplies to power the 12 digital meters.
The digital voltmeter connections are pretty straightforward. Each voltmeter will measure a cell voltage and therefore the negative (-) and sense wires need to go across the individual cells.