The outgoing warm stale air, heats the incoming cold air.
It is important to clean and replace filters on a regular basis. Boards.ie has an interesting discussion on this topic and the fact that irish government are going to issue guidelines on this.
1) Scheme covers cavity wall insulation and or attic insulation (in standard pitched roofs....flat roofs / dry lining etc. not covered.) in national schools built before 2006
2) Scheme covers quilt type insulation in attics (fibre glass or rock wool, blown in products excluded) and EPS bead or similar for cavity wall (foam excluded)
3) Scheme covers 100% of the cost
4) School needs to get 3 No. quotations from approved suppliers. Approved suppliers are the same as those registered for SEI HES Scheme
5) On completion school needs to hire engineer, architect or suitably qualified person to verify that work has been carried out (€200 provided by dept to fund sign off inspection)
6) Dept has set out minimum specification to be achieved
See fpisolar.ie and energyeducation.ie for more info
If you are considering building an energy efficient house, I would recommend that you read the whole house book. This book originally published in 1998 but updated in 2008. It covers all aspects of a sustainable building project. With numerous case studies which highlight the improvements that can be made to a structure it shows the reader how small changes can generate big results.
The CAT centre in Wales publish this book, this centre has been implemented "green technologies" since the 1970s, some of which are only becoming mainstream now.
My colleague Bernie Goldbach wrote an article in April in relation to the greener homes supplement in the Sunday Times. This supplement appeared again this weekend (21st June 2009) the articles prompted me to mention this book. There is a renewed interest in sustainable design, this is something we teach and specialise in Tipperary Institute. We use this book as the student text book for our Advanced Certificate in Domestic Sustainable Energy
Greenwash (a portmanteau of green and whitewash) is a term used to describe the practice of companies disingenuously spinning their products and policies as environmentally friendly, such as by presenting cost cuts as reductions in use of resources.[1] It is a deceptive use of green PR or green marketing. - Wikipedia article
A company in roscrea are rating their Wizzmill wind turbine as 2.8kw at 22.5 meters per second. The turbine has a diameter of 1.8 meters.
In their FAQ section they state that "It will produce up to 2.8kw on a windy day (50-70 mph wind)"
I did not record that wind speed once during a 1 year analysis of the wind.
At 10 m/s my wind swept area analysis concludes that is capable of 0.62 Kw i.e 620 Watt turbine.
They also claim that a height of 5 -6 meters is plenty. This is also very questionable, unless the turbine is 120 meters away from a building 5 -6 meters in not plenty.
I rang the company and asked for some more information on the product. They claimed that it provides 1 kw at 6 m/s.
Using wind swept are calculations I analysed the turbine and my calculation concluded that it provides 0.13kw (130 Watts) at 6 m/s. They then confused the amount of energy generated in a day against the amount of energy generated in an hour at a particular wind speed.
| Rotor (Meters) |
Rotor feet | m/s | mph | Kw |
| 1.8 | 6 | 3 | 6.75 | 0.016784 |
| 1.8 | 6 | 4 | 9 | 0.039785 |
| 1.8 | 6 | 5 | 11.25 | 0.077706 |
| 1.8 | 6 | 6 | 13.5 | 0.134276 |
| 1.8 | 6 | 7 | 15.75 | 0.213225 |
| 1.8 | 6 | 8 | 18 | 0.318283 |
| 1.8 | 6 | 9 | 20.25 | 0.453181 |
| 1.8 | 6 | 10 | 22.5 | 0.621647 |
| 1.8 | 6 | 11 | 24.75 | 0.827413 |
| 1.8 | 6 | 12 | 27 | 1.074206 |
| 1.8 | 6 | 13 | 29.25 | 1.365759 |
| 1.8 | 6 | 14 | 31.5 | 1.7058 |
| 1.8 | 6 | 15 | 33.75 | 2.09806 |
When I requested some information on the turbine and the manufacturer data the phone conversation dropped several degrees and they wanted to know If I wanted the business also. They promised to send out some info via email, I am still waiting.
Buyer beware, do your home work and do request the manufacturer specs. If they don't want to provide them, then vote with your feet.
Update 17-June 2009. This product is also being offered by www.westairenergy.com which is a sister company of http://www.architectureenergy.ie/
The same claims are being made by this company, without any proof.
Update July 2nd 2009.
I used retscreen to some financial analysis on this product.
Asuumptions.
Cost 1950 + 400 for 6 metre pole and connection to hot water tank. Total price 2350.
Hub height 6 meters.
Wind speed 6.5 at 50 meters, this equates to 4.5 at 6 meters
Array
losses
%
2.0%
Airfoil losses
%
2.0%
Miscellaneous losses
%
2.0%
Availability
%
97.0
Wind shear exponent 0.17
Electricity priced at 16 cent per unit
Fuel
cost escalation rate
%
5.5%
Inflation rate
%
2.5%
Discount rate
%
Project life
yr
20
Pay back is 16.5 years.
In order to achieve a payback of 3 years as the website claims I would need the following wind speed.
50 meters 12.3 m/s
at 6 meters 8.6 m/s
This would mean that the turbine would have a capacity factor of 88% which is unheard off, modern large wind turbines such as the 90 meter tall variety have capacity factors between 20 and 40 %.
In my estimation the wizzmill has a capacity factor of 16%
There are very few locations in Ireland that have wind speeds of 12.3 m/s at 50 meters.
.
I am attending the Tipperary Energy Agency training course on RETScreen
RETScreen is a tool used for PreFeasibility and Feasibility Analysis. It is developed by the Canadian government. It requires relatively little user input and calculates the technical and financial viability automatically.
I would like to see RETScreen being used to estimate wind turbine and solar photovoltaic output and return on investment.
I have heard on the news and seen on irish websites claims of payback times for wind turbines of 8 - 12 years. These websites and company reps do not provide any data regarding the calculation or how these figures were derived.
Will these companies who state payback in 10 years, refund the cost of the turbine if after 2 - 3 years it is apparent that the turbine will not pay back in 10 years?
The spurious claims being made by some sales reps at energy shows and on web sites will come back to haunt us in 18 - 24 months, when radio chat shows will be clogged with angry people ranting about the fact that the payback is not being achieved. Do we want the 6 pm news doing a wood pellet type report on domestic wind turbines? The renewable energy sector needs to clean up its act and set standards for sales of renewable products.
How can some one state a payback to a client with out viewing the site?
I learned an important lesson about wind turbines, I measured my wind speeds for 1 year and at least I have factual data to help me make my decision.
Even though I live in a windy area my site is not great. There are better sites out there that are suitable for turbines, but how can the consumer make an informed decision?
We need to measure wind speed first, companies are under pressure to generate sales so if they are competing with cowboys who are telling porky pies about payback, what can they do, do they match their claims?
Any state assisted programme for wind turbines should mandate measurement of wind speed before the turbine is installed. I would recommend 6 months minimum measurement. Consumers should be made more aware about demanding calculations, results etc
Companies should produce factual energy output measurement and recorded data for energy production from at least 5 different sites. Sound levels should be measured from 20, 40 and 60 meters.
As part of a sales quotation companies should include a calculation from an application such as RETscreen which would indicate the kw hrs being produced, this would be backed up with the recorded wind speed analysis.
Some companies can provide data on the output generated by their turbines across different countries and different locations. My instinct is to trust these companies above a company that starts business on a Monday and imports a turbine from China on a Tuesday so as to sell it on a Wednesday.
There are videos on youtube where enthuastic wind turbine installers have installed wind turbines and mentioned the figures being generated. I did my sums and the payback for that installer was 30 years plus. The problem was the site. That same wind turbine would have a payback time of 26 years on my site based on their cost.
The domestic wind turbine is fraught with issues that must be addressed in an open and transparent manner. We have the potential to benefit from this great resource but this can only be achieved using an ethical and honest approach.
If you are interested in learning some more on Wind Energy, you might consider reading this book.
I have recently measured wind speed in my back garden for 1 year from April 23rd 2008 to April 23rd 2009 at 4 m. We live in Upperchurch in Co. Tipperary and the area would be considerd by locals and visitors a windy place all year round, and bleak spot in the winter. I then applied a scaling factor of 0.61 (i.e. divide the reading by 0.61) to bring the wind speed up to 10 m height this figure was based on data provided by http://www.sustainability.ie/microwind.html and had a higher shear factor than RETscreen recommended i.e. I was generous in my estimation.
Accorrding to the wind maps the wind speeds for Upperchurch are 6 - 6.25 m/s at 50 meters. At 10 meters my average measured wind speed was 3.83 ms (this is upscaled) the measurement at 4 meters was 2.3363 m/s .
Number of hours for each wind speed were as follows.
| April 23 2008 - April 23 2009 extimated wind
speed at 10 meters height |
|||||
| m/s | Hours | ||||
| 0 | 1261.833 | ||||
| 1 | 747.4167 | ||||
| 2 | 890.8333 | ||||
| 3 | 1443.333 | ||||
| 4 | 1395 | ||||
| 5 | 1040.583 | ||||
| 6 | 393.4167 | ||||
| 7 | 597.5833 | ||||
| 8 | 390.75 | ||||
| 9 | 243.9167 | ||||
| 10 | 84.91667 | ||||
| 11 | 110.9167 | ||||
| 12 | 75.16667 | ||||
| 13 | 40.91667 | ||||
| 14 | 23.25 | ||||
| 15 | 20.16667 | ||||
Using Mike Sagrillos Wind Swept Area Calculations I generated a payback table based on wind turbine diameter only I calculated the income that would be generated from selling back to the grid. The first 3,000 KW hrs are priced at 19 cents and the remainder at 9 cents.
The results are as follows:
| Diameter (meters) | Turbine Output at 10m/s | Kw Hrs | Income |
| 2 | 0.77 | 1159 | 220 |
| 2.2 | 0.93 | 1402 | 266 |
| 2.4 | 1.1 | 1669 | 317 |
| 2.6 | 1.3 | 1958 | 372 |
| 2.8 | 1.5 | 2271 | 431 |
| 3 | 1.7 | 2608 | 495 |
| 3.2 | 1.96 | 2967 | 563 |
| 3.4 | 2.2 | 3349 | 601 |
| 3.6 | 2.48 | 3755 | 638 |
| 3.8 | 2.78 | 4184 | 676 |
| 4 | 3 | 4636 | 717 |
| 4.2 | 3.4 | 5111 | 760 |
| 4.4 | 3.38 | 5111 | 804 |
| 4.6 | 4 | 6131 | 851 |
| 4.8 | 4.4 | 6676 | 900 |
| 5 | 4.8 | 7244 | 952 |
| 5.2 | 5.18 | 7835 | 1005 |
| 5.4 | 5.59 | 8450 | 1060 |
| 5.6 | 6.02 | 9087 | 1117 |
| 5.8 | 6.45 | 9784 | 1177 |
| 6 | 6.9 | 10432 | 1238 |
These figures should help you to estimate the payback time. Look up the turbine's diameter and look across to the income.
A breakdown for a 3 meter radius turbine is provided below
| 3 meter radius turbine | ||||||
| Rotor M | Rotor feet | m/s | mph | Power (kW) | Hrs | Energy (kWh) |
| 3 | 10 | 3 | 6.75 | 0.046624 | 1443.333 | 67.29332 |
| 3 | 10 | 4 | 9 | 0.110515 | 1395 | 154.1685 |
| 3 | 10 | 5 | 11.25 | 0.21585 | 1040.583 | 224.6096 |
| 3 | 10 | 6 | 13.5 | 0.372988 | 393.4167 | 146.7398 |
| 3 | 10 | 7 | 15.75 | 0.592292 | 597.5833 | 353.9436 |
| 3 | 10 | 8 | 18 | 0.884121 | 390.75 | 345.4701 |
| 3 | 10 | 9 | 20.25 | 1.258836 | 243.9167 | 307.051 |
| 3 | 10 | 10 | 22.5 | 1.726798 | 84.91667 | 146.6339 |
| 3 | 10 | 11 | 24.75 | 2.298368 | 110.9167 | 254.9273 |
| 3 | 10 | 12 | 27 | 2.983907 | 75.16667 | 224.2903 |
| 3 | 10 | 13 | 29.25 | 3.793775 | 40.91667 | 155.2286 |
| 3 | 10 | 14 | 31.5 | 4.738334 | 23.25 | 110.1663 |
| 3 | 10 | 15 | 33.75 | 5.827943 | 20.16667 | 117.5302 |
| Total Kw | 2608.053 | |||||
| Income | 495.53 |
|||||
If you are interested in learning some more on Wind Energy, you might consider reading this book.
As a user of linux I take it for granted that I can create PDF documents. It is not as straight forward for Window OS users.
I have been asked in the past to recommend an application for creating PDF documents. The application I use in Windows is CutePDF which installs a printer in Windows.
It can be downloaded from http://www.cutepdf.com/Products/CutePDF/writer.asp
You need to install the PS2PDF converter first, the link for this software is on the page.
Happy PDFing.
I have been asked in the past to recommend an application for creating PDF documents. The application I use in Windows is CutePDF which installs a printer in Windows.
It can be downloaded from http://www.cutepdf.com/Products/CutePDF/writer.asp
You need to install the PS2PDF converter first, the link for this software is on the page.
Happy PDFing.
Urban wind have some very interesting documents on European urban wind turbine manufacturers and an explanation of the terminology
http://www.urbanwind.net/downloads.html
A list of European urban wind turbine manufacturers http://www.urbanwind.net/pdf/CATALOGUE_V2.pdf
Urban Wind Turbine technology review, which has a good explanation of noise from turbines
http://www.urbanwind.net/pdf/technological_analysis.pdf
http://www.urbanwind.net/downloads.html
A list of European urban wind turbine manufacturers http://www.urbanwind.net/pdf/CATALOGUE_V2.pdf
Urban Wind Turbine technology review, which has a good explanation of noise from turbines
http://www.urbanwind.net/pdf/technological_analysis.pdf
A renewable energy colleague of mine in Tipperary Institute pointed me towards this excellent document created by the British Wind Energy Association. The standard recommends measuring at 11 m/s, I would prefer to measure at 10 but I cannot argue with the rest of the excellent research.
This standard was created by the small wind turbine industry, scientists, state officials, and consumers to provide consumers with realistic and comparable performance ratings and an assurance the small wind turbine products certified to this standard have been engineered to meet carefully considered standards for safety and operation.
The goal of the standard is to provide consumers with a measure of confidence in the quality of small wind turbine products meeting this standard and an improved basis for comparing the performance of competing products
This performance and safety standard provides a method for evaluation of wind turbine systems in terms of safety, reliability, power performance, and acoustic characteristics.
http://www.bwea.com/pdf/small/BWEA_SWT_Standard_Feb2008.pdf
This standard for small wind turbines is derived largely from existing international wind turbine standards developed under the auspices of the International Electrotechnical Commission (IEC).
Specific departures from the IEC standards are provided to account for technical differences between large and small wind turbines, to streamline their use, and to present their results in a more consumer-friendly manner.
The equivalent BS (British Standard) are quoted for ease of use.
http://www.bwea.com/pdf/small/BWEA_SWT_Standard_Feb2008.pdf
This standard was created by the small wind turbine industry, scientists, state officials, and consumers to provide consumers with realistic and comparable performance ratings and an assurance the small wind turbine products certified to this standard have been engineered to meet carefully considered standards for safety and operation.
The goal of the standard is to provide consumers with a measure of confidence in the quality of small wind turbine products meeting this standard and an improved basis for comparing the performance of competing products
This performance and safety standard provides a method for evaluation of wind turbine systems in terms of safety, reliability, power performance, and acoustic characteristics.
http://www.bwea.com/pdf/small/BWEA_SWT_Standard_Feb2008.pdf
This standard for small wind turbines is derived largely from existing international wind turbine standards developed under the auspices of the International Electrotechnical Commission (IEC).
Specific departures from the IEC standards are provided to account for technical differences between large and small wind turbines, to streamline their use, and to present their results in a more consumer-friendly manner.
The equivalent BS (British Standard) are quoted for ease of use.
http://www.bwea.com/pdf/small/BWEA_SWT_Standard_Feb2008.pdf
