What is the real cost of Solar Energy ?

With the soaring cost of electricity in Jamaica, many persons are ready to crucify the OUR and JPS as it appears that the  two are in collusion to rip off the public.
There is a tremendous amount of emotions involved , with many persons showing bills which they have indicated have increased tremendously for no apparent reason.

The question of alternative energy sources have been championed once again, and always occurs when oil goes up which results in an increase in the cost of electricity. I too am in favour of an energy mix, of which renewable energy sources must be an integral part of that mix.
But what is the real cost of solar installation and can the average consumer really save money by installing such a system for their homes.

I have decided with the help of other resources to really break this down to see if this is just a lot of emotions ar work or can we really save at today's by installing such a system.

Lets first talk a little about demand in trying determine what kind of solar system one would need to extraciate themselves from the JPS grid.
A middle income family with say a 4 brm 's house may containing the following .

• 1 18 cubic ft refrigerator      -      420w (0.42kw)
• 1 x 16 cf freezer (NF)         -      600w (0.60kw)
• 1 x 12,000 btu ac unit -       -      3.5kw
• 1 micro wave                      -      1.2 - 1.5 kw
• 1 clothes iron                      -      1.5kw
• 1 washing machine              -      500w (0.5kw)
• 1 dryer                               -      2.7kw
• Toaster oven                      -     1.5kw
• Hair Dryer                          -    1.15kw
• Dish washer                        -    1.2kw
• Lighting (CFL)                    -    220w (0.22kw)
• Flat screen tv(42")              -    150w (0.15)
• Home Ent System               -    400w ( 0.4kw)
• 40 Gal water heater            -    3kw
• Other                                 -    500w (0.5kw)

Aggregate demand = 17.24Kw

Now we would never have all the above equipment running at the same time so lets use a load factor of say 30% , this means no more than 30% of the aggregate demand would be on at any one point in time.

Total average demand = 17.24 x 0.3 = 5kw ( Actually 5.17kw but I am using 5 for ease of calculation).

Cost of 5Kw Solar system

The cost of a solar grid tie system( NOT  installed) in the USA is estimated to be in the order of US $25 - $28,000 so lets use $26,000. Then for installation of the system and tie into JPS( net metering when it comes on board) lets add another $5000, for a total cost of US$31,000.

Assumptions.

1. Lifetime on panels 20 - 25yrs
2. Life time on inverter - 10 -15 yrs
3. Average life span of entire system lets say 20 yrs.
4. Efficiency of converting light to dc then inverting to ac  lets say system is 90% efficient.
5. System generation is 5hrs per day, ie period when sun is most prominent ( 9am - 2pm)

• Now system capacity is 5kw x 0.9 = 4.5kw but manufactures does not want you to run it at its max capacity so the max load they indicate is  4kwh.
• Total energy produced over the system life span = (#hrs per day we are generating power x # days per yr x total power produced x life span ) = 5 x 365 x 4.5 x 20   = 164,250Kwh

Given actual max rating of 4kw total available power = 5 x 365 x 4 x 20 = 146,000 kwh

Calculations

1. System installation cost per kw = System cost(installed) / System Capacity                                                                                                            

                                                           = $31,000/ 5 = US $6,200 / kw

     2.  Cost per kwh over the life time of the equipment = Total system cost(installed) /rated kwh available

                                                                                    = $31,000/ 146,600

                                                                                    = US$0.21/kwh

How does JPS compare to the above

At today's rate the residential customer is paying on average of US$0.39/ kwh so does this mean the customer who purchase this system and switched fromo JPS would save $0.18/ kwh over the life of the equipment. Not necessarily as recall the total aggregate demand for the customer was over 17Kwh.

Even when we dropped the load factor to 30% , the demand was 5Kw and this system is only producing usable power of approx 4kw.

This therefore leaves a short fall of minimum 1kw which must come from somewhere, either from JPS or another renewable energy source such as wind. The customer may also choose to go to say a 10kw system which would move the cost to over  US$50K installed.

Now lets assume the individual opts to use JPS (he has  a grid tie system)

How this grid tie system works is I can either use my system and sell the excess to JPS and get a credit, or if my system goes down I have JPS as back up. These new electronic meter allows for co-generations recordings ie it records what is generated in the house and what is generated from outside (JPS).

The individual would need the minimum demand of 1kw and say this demand is used 5hrs per day , then the total consumption per day would by 5kwh/hr.

Weight average cost of electricity becomes  $0.246/Kwh

Calculation  JPS 1 Kwh @ 0.39/kwh   = $0.39

Solar =    4 Kwh @ 0.21/kwh             = $0.84

5 kwh   = US$1.23

So cost per kwh = US$1.23/5 =  $0.246/ Kwh

The above is an over simplification as we ignored the following.

1. Shipping cost 
2. Duties applicable to the above (duty free status was removed)
3. Cost of capital ( if person is borrowing)
4. Time value of money.
5. Losses from exchange rate conversion and fluctuations.

When the above are taken into account we could very well be adding another 8 - 10 cents (US) per kwh hr, thus moving this cost to $0.32 - $0.35 /kwh.
However as time goes on the cost of solar system will fall and if oil keeps rising, the reverse could be occur where the saving as actually greater than those stated above.

Lets look at the graphs below credits have been noted.  It speaks volumes.

How did I beat JPS high energy bills

With black Friday being declared for Friday, Aug 19, 2011 I thought I would share with bloggers my bills for the last four months of this year.
This house is unoccupied for most on the time and is probably used 4 days per month. It uses  mainly  fluorescent bulbs, but also incandescent bulbs 7 x 40w controlled by 3 electronic dimmers switches as follows. 4 for two bathrooms and 3 in the living room. ( I plan to get rid of these in the new two months or so).

The appliances are a 18 cf  no frost refrigerator and a electric water heater which is only used maybe days per month, while the home is occupied. The refrigerator however remains plugged in all the time.
The meter is an analog electro-mechanical meter like most of what we as Jamaicans at our homes.

Just a little history, 6 years ago I got a bill from the JPS which immediately struck me as being inaccurate. I went and read the meter myself and realized that the reading on the my bill was far different from what I noted on the meter. In fact the reading noted as present reading on my bill had not yet been recorded on my  meter ie the meter had not yet reached those levels.
Armed with pictures of the face of the meter, the actual readings I had recorded along with a copy  of my latest bill, I wrote a very strongly worded letter to the corporate office, which surprisingly responded within two weeks.

I got an apology and I was not billed for two months by which time my "real readings" had caught up with the "bogus" reading that had been on my bill. Since then I really have never had a problem with the JPS and my readings have been accurate since then.

Now for my bills this year when most persons are seeing increases.

Digital Meter complaints, real or imagined

This afternoon(Monday , 8/15/2011) I listened to an interview between Nationwide News Network Cliff Hughes, the manager of JoJo's and Dr Hamilton of the SME's in Jamaica.
The subject was high utility rates being experienced by both residential as well as SME member, KVA demand charges and the new smart meters being installed by the JPS.

I have already addressed the KVA demand charges and while I hear people saying JPS is "wicked" in the way demand charges have been applied, its not different from how all other utilities applies this charge. In fact its very consistent, and what many seem not to have recognized, is that JPS has in fact lowered the penalty from 11 months to 5 months.

As it relates to the new smart meter, the Jamaican experience has been identical to what customers of Portland, Electric and Gas (PG&E) in Texas experienced when that company started installing these new meters.

See the following link.
http://www.smartmeters.com/the-news/690-pgae-smart-meter-problem-a-pr-nightmare.html



As you can see from the above link, the Jamaican situation is almost exactly the same, read my post " New electronic meters could mean higher electricity bills to see why".


Now the problem has been so bad and complaints have been so fast coming that a consulting company was brought in to commission a study to explore wether or not these complaints where real ie where these new meter accurate and were they recording more than the old electromechanical analog meters.

The summary of the document in the Texas experience suggest that customers consumption patterns tends on increase around certains periods of the year , which is the same point in time that the cost of the utlilty charges were usually higher. In effect the customers say significant increases in there bills due to their consumption pattern vs over recording of the new meters.

I have attached a copy of the document for your perusal, its over 170pgs long and as is the case with many Jamaicans we simply refuse to read, thus we always tend to be a victim, as we are an uninformed society.

Recently I wrote to a company offering free service of analysis of their utility bill after seeing their complaint, three weeks later they have refused to take up the offer which is no longer on the table.

We can either chose to complain or on the other hand chose to educate ourselves thus allowing us to be more strident customers , who makes better decisions as it relates to the operations of our homes or businesses, the choice is yours.

See the link below " Evaluation of advanced (smart) meters.
https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B_NeVEvMNIivZDU3ODc2YWItN2M3Ny00YmQzLWJmODYtNmFkOTAwYzhlOTg0&hl=en_US

New electronic meter could mean higher electricity bills.

As the Jamaica Public Service moves to replace the very reliable analog (rotating disk) meters with the newer electronic meter, which allows for easier data collection of the power consumption of the customer, there could be “problems” ahead for the customer.

The old rotating disk and dial meter as they are known was built to ANSI C12.1 standard and has recording error of around 4% (i.e. +/- 2).  What this really means is that the meter could record anywhere between 2% higher or 2% lower than your actual consumption.

The new electronic electrical meters used for residential customers however are built to ANSI C12.20 and rated at class 0.5 which has an error of only 1% (i.e. +/- 1). While this is good for the utility company it could mean “bad” news for the consumer,  simply because  its more accurate.

In addition to the above , while the analog meter was only able to measure electricity down to 0.3A  (66W) on a 220V supply, these new digital meters are able to measure electricity down to 0.1A (22W).  Think of it this way your old meter would allow 3 x 22W fluorescent bulbs to run and would not be able to record this, however with the digital meter only 1 bulb could be on before this new meter will detects its on.

Electromechanical (Analog) metering issues.

As can be seen from the graph below (courtesy of EPRI) the analog meter shows loss of registration over time and this is outside of the intrinsic error of  +/- 2% in the design of the meter.

Now if you have a meter for say ten years it could be recording at say 99.2 % of your actual consumption and when the error is added this could be as low as 97.2% of the actual consumption.

These analog meters “slowdown” over time due to aging, dirt, insect and other types of debris resulting in the meter under recording your consumption. Now if you have a meter, which has been under-recording for sometime, you could be in for a shocker when these new  and more accurate digital meters are installed.

See this additional graph below again provide by EPRI which shows that in a sampling of over 400,000 meters in the states approx 0.3% of the “population” have meters recording between 10 –20% lower registration that they should i.e. they were recording only 80 –90% of the electricity consumed.

This problem shown here however disappears with the installation of the new electronic meter and therefore the residential customer so affected, sees an immediate increase in not only his consumption but also his bill. ( Between 10 – 20% increase would be observed)

In time of rising energy cost in Jamaica this is a double blow as with the ever increasing cost of fuel, the change in our bills are more pronounced as a 5% increase in consumption could result in an increase of greater than 5% based on the every increasing fuel charge component of our bills.

Voltage instability & Transients.

Electronics are very susceptible to surges, spikes, transients and harmonics. The ANSI C21.1 metering standards specifies the magnitude and amount of surges these meters are expected to withstand, so as to address this problem, which was never an issue with analog meters, which had an air gap, which was used to dissipate these energies.

The big question is apart from the design mandate by ANIS C12.1 and ANSI C 12.20 does the JPS uses any additional circuit protection to avoid damage to these meters, which could affect their readings.

So having said all the above, what can we do about it?

Not much really, the best way as I have said on a number of occasions is energy conservation as well as being aware of your meter readings i.e. read the and record your own meter reading as close as possible to when the JPS meter reader usually comes.

I am asking readers to assist me with some information.

For those who currently have a digital meter can you provide the following on this blog:

1. Make/Manufacturer of the meter.
2. Date of manufacturer
3. Any additional information that is recorded on the meter.

Note : I do NOT need your meter number

Continue to watch this blog for information relating to energy and its management.