Looking for a tender manager BoP

Looking for a Tender Manager specialized in Turnkey (EPC) wind farms.

Ideally expert in wind farm Balance of Plant (roads, foundations, MV cables, substation) and technical and commercial negotiations for all BoP scope of supply.

Apply on Linkedin or here:

https://nordex-jobs.dvinci.de/cgi-bin/appl/selfservice.pl?action=jobdetail;sid=2ctve7ap88m7y3oy;job_pub_nr=06A416E2-A75E-454C-AB00-5062D288C634;p=homepage;job_pub_type=extern;

5 strange things that you might find in a wind farm

Working on a variety of projects worldwide I sometimes see unusual requests from customers that want to complement their new wind farm with some nonstandard feature.
I’m collecting here my personal top 5 of “...are you REALLY sure you want it?”. Even if often this type of requirements can lift considerably the price (and make the project less attractive) customers are often irremovable in their request.

#5 – Reserve main transformer. Sometime also poetically called “cold transformer” this is basically a very expensive spare parts to keep parked somewhere in the substation. With a price tag around 1 million it looks like a very expensive price to pay to have a backup in case something goes wrong with the main transformer.

#4 – Residences for the Service technician. In very big wind farm sometimes it’s a good idea to have someone on site 24/7. If the wind farm is in the middle of nowhere it can be also a good idea to provide fully furnished houses.

#3 – Gym. The same Service technician living in the middle of nowhere will presumably need something to do while they are off duty. A properly equipped gym can provide a good use for their spare time.

#2 – Mosque. With a mosque we are becoming very near to the concept of “wind farm town”. It was also a good opportunity to learn something more about the various requirements of this type of religious building.

#1 – Watchtowers. By far the most unusual requirement ever. Basically, a place where an armed guard can watch from a vantage point who is approaching the wind farm, with electricity (you will need to connect it to the substation somehow) and septic tank.

Environmental impacts of wind farms

When I talk about my job with people coming from different businesses I receive often question linked to the “environmental impact” of wind turbines.

This term include various effect related to the construction of a wind farm. They can be summarized in the following categories:

Visual impact

Are wind turbines ugly or not? This is a difficult question. Probably I’m biased, but I think they are beautiful – or at least, better than a nuclear plant, unless you like concrete cooling towers. Some nacelles shape have been designed by artist (like the first Acciona models) or architects, like Enercon’s egg shaped solution. It has been designed by Sir Norman Foster and has been awarded with the Design Council Millennium Products Award, the same prize given to beautiful stuff like the Lotus Elise.

However in several countries a specific study is done to evaluate the visual impact of the turbines. There are several indicator and methodologies, however this is usually done considering the “weighted” average height of the horizon before and after the construction of the wind farms.

Noise generation

New generation turbines use a lot of tricks to keep noise low. Noise is coming above all from the tip of the blade, being the rotating equipment in the nacelle only a secondary source. The “easy” way to limit noise is limit the tip speed of the blade. Other strategies involve special profiles for the blade and software control of the machine to limit noise emission when needed (usually during the night, and/or when the wind is blowing from specific directions).

Electromagnetic interferences

This is easy to measure. In general electricity is generated at a low voltage (around 700 Volt) and MV cables are buried, so this impact is negligible.

Shadow flickering

This is the risk that someone living near the wind farm could experience, for a prolonged length of time, the intermittent shadow of the blades passing in front of the sun. This impact is relatively easy to simulate: there are software that, given the position of the turbines and the meteorological parameters (wind direction, percentage of sunny days) calculate the amount of time an observer located somewhere near the turbine would experience the flickering.

Bird strikes

One of the most discussed issues. You will find quite a lot of studies online, done in countries were wind energy and environmental sensibility is well developed (US, Germany, Spain, etc.). In general my impression is that, compared with other causes of bird death (hunt, high buildings, traffic, etc.), impact with turbine is accountable for a very small percentage.

Additionally modern wind turbines can be equipped with a lot of technology that minimize this risk (bat detectors, LIDAR systems, artificial vision, etc.). I had the pleasure of working at projects were the space between machine was large enough to lower the risk of impact, and additionally the turbines were stopped when migrating birds approaching the wind farms were detected.

 

Wind farms: top 5 of myths & urban legends

A curious consequence of writing a blog about wind farms is that every now and then I’m contacted by someone hating wind energy.

In the majority of the cases, the writer also ask for help to stop or boycott a wind farm somewhere in the word, apparently ignoring the fact that wind turbines help me to bring food on the table every night.

To add insult to injury, in the emails they often ask me support to confirm some pseudoscientific “facts” about wind turbines.

I’ve collected some of them in this post – other are coming from anti-wind energy propaganda websites that I read on the subway when I’m bored to discover new, unexpected effect of windmills.

Some of them are similar to the urban legend of the albino alligator in the sewers of New York.

Feel free to contribute!

5. Wind farms causes bush fires. Well, it’s true that (very, very infrequently) a wind turbine burns somewhere. But to say that they are burning woods and bushes it’s a bit too much.

4. The foundations are poisoning the water. Unless you pump 1 million cubic meters of bentonite to do a piled foundation nothing will happen to the water – a foundation is basically only a big stone.

3. The turbine is scaring the fishes – I’m not fishing as much as before. This is courtesy of a fisherman in Juchitan de Zaragoza (Oaxaca, Mexico). I doubt that a fish 10 meters underwater can really hear a WTG.

2. You need more energy to build a wind farm than the energy produced by the turbines. I’ve seen several (serious, scientific) papers on the subject. The energetic payback is usually only a few months.

And the winner is...

1. Wind farms change the weather locally. I love this one. The theory is that, slowing the wind, wind farms modify somehow the climate in the area – some urban legends say that they warm it, some others that they make it more foggy. Well, at least here in norther Germany where I’m living they are not making it any warmer.

Acronyms in wind farms construction

I’ve been informed by one of my most affectionate reader that some acronyms that I’m using in the blog are not immediately clear.

Therefore I’ve started a first list of the most used ones - special thanks to Janos for helping expanding the list:

AEPAnnual energy production.
BoPBalance of plant. All civil (roads, foundations, crane pads) and electrical works (cables, substation, etc.) in the wind farm.
CapExCapital Expenditures
CODCommercial operation date
COECost of energy
EISEnvironmental impact sudy
EPCEngineering procurement and construction. A type of contract (also known as "turnkey")
FIDICInternational Federation of Consulting Engineers  (Fédération Internationale Des Ingénieurs-Conseils)
HSHealth and safety
HVHigh voltage
IPPIndependent power producer
IRRInternal Return Rate
LDLiquidates damages
MLAMechanical Load Assessment
MVMedium voltage
MWMegawatt
O&MOperation and maintenance
OEMOriginal equipment manufacturer. Here, the company producing the wind turbine.
OMAOperation and Maintenance Agreement (sames as SMA)
OpExOperation expenditures
PCCPoint of common coupling
PPAPower purchase agreement
RoWRight of way. The legal right to use a certain route.
S&ISupply and installation
S/SSubstation
SCADASupervisory control and data acquisition
SMAService and Maintenance Agreement (same as OMA)
SoWScope of work
TSATurbine supply agreement. The contract between the wind turbine manufacturer and the wind farm developer.
W&SWind and site. Usually, either the assessment of the wind farm (W&S study) or the department doing it.
WFWind farm
WTGWind turbine generator

Technical due diligence of a wind farm

It is a hard task to compress in a blog post the reasons behind the technical due diligence of a wind farm and the several points that must be evaluated.
In a nutshell, in the clear majority of the wind farms developments are built using borrowed money.
The equity (cash at risk) is put by the developer, while the debt (money given against some form of security) is provided by a financial institution, or more commonly by a pool of institutions.
There are obviously exceptions to this rule, that is wind farms developed only with cash coming from the books of the company investing in the project. Nevertheless, these are exception and what is common is to have most the budget (up to 70%) provided by a financial institution such as a bank.
The lenders will be obviously interested in being sure that the financial model behind the project is solid.
Therefore, they will ask for a due diligence to identify, quantify and (if possible) mitigate technical risks.
In general, the lender will check what he considers appropriate.
Normally 3 macro categories are checked:

Financial due diligence, including for instance

  • Hypothesis
  • Budgets
  • Financial models

Legal due diligence, including items such as

  • Land lease
  • PPA
  • Contracts (e.g. TSA) & subcontracts

Technical due diligence

There is obviously an overlap between the various categories – for instance, some items are not purely “technical” or “legal”.
The technical due diligence should investigate in detail several key points.
A short, non-exhaustive list would include at least the following items:

  • Site suitability (wind resources, turbulence, data solidity)
  • Choice of WTG model (track record and match with the wind resource, power curve, certification, etc.)
  • Archeological y environmental constrains (impact on flora and fauna, such as birds and bats)
  • Access to the area (road survey and works outside the wind farm)
  • Geotechnical survey (ground risk)
  • Noise study (a big problem in inhabited areas)
  • Shadow flickering & visual impact
  • Grid connection
  • Electrical losses (are they calculated correctly?)
  • Projects for the BoP (foundations, MV, substation, etc.)
  • Congruence of the time schedule of the project
  • Interface between subcontractors
  • Allocation of risk

EWEA 2016

Some days ago I’ve had the opportunity to spend an afternoon at the EWEA summit, the European Wind Energy Association main event.
It was held in Hamburg, city where I have the pleasure to live since December 2015, and it was simply HUGE.

This year, both onshore and offshore were held together, resulting in an impressive amount of stands.
Unfortunately, I wasn’t able to meet too many new company specialized in onshore EPC (my main business).

However, I was able to enlarge the list of contact in engineering companies – coming from several years in Madrid I know fairly well who is who in southern Europe, while I still have to familiarize more with northern Europe consultancies (mainly Danish, but also German or French).

All in all, it was a very interesting experience and a great occasion to meet a couple of old friends.

Unmanned aerial vehicle (UAV) topography

This is a new technology we are going to use in a wind farm we are going to build in Chile.

The area that we need is too small to make LIDAR topography cost effective, but too big to use standard field topography: with this new solution we can have the needed data for a reasonable price.

The vehicle comes in 2 shapes: airplane like (fixed wing) and helicopter like (rotatory wing). The fixed wing plane is launched with a sling.

The vehicle weight around 3 kilos, and it can fly for about 1 hour at a height of a couple hundred meters, with a speed of about 75 Km/h.

It is possible to obtain several useful outputs:

  • Cartography
  • Digital Model of the Terrain
  • Aerial pictures
  • Thermography
  • Multispectral images
  • Video

It normally flies alone without any input, but it can be used with a remote control as well.

The main advantage is that it is clearly cheaper: you don’t need to book a flight, wait for a days without clouds (because you can fly lower) and it’s quick and safe.

 

Wind farms projects using Google Earth topography

One of the biggest problems in wind farms preliminary projects is the lack of a reliable topography.

Due to the tight budgets developers are often working with, it is often impossible to obtain a good topography (like the ones you can get with a LIDAR instrumented flight) or at list a decent one (as the standard field topographic surveys).

One of the possible solutions is to work with the Google Earth topography. Software like AutoCAD civil 3D makes it possible to download a cloud of points with coordinates and elevations and work with them.

The question is: how good is this info?

Unfortunately it’s impossible to answer univocally. The base grid, covering almost all the inhabited surface of the planet, has been obtained with a space mission (the NASA SRTM, Shuttle Radar Topography Mission).

The points are approximately spaced 50 meters, so it is a very rough starting point.

This base has been integrated with a “mosaic” of different DEM (digital elevation models) freely available material, so there are states in the US with a 1 meter contour line, or even cities with a very dense cloud of points (even a point every 20 centimeters).

It is currently impossible to know from where the points you are using are coming from, and if a point is “true” or interpolated. It is possible to have an impression seeing the shape of the contour lines (if you “zoom out” from the topography you will often see a pattern of squares coming from the available points).

This data is normally reasonably acceptable for a somehow preliminary project. Several commercial plug in are available to enhance the results.

For instance Plex Earth allows you to import Google Earth data (pictures and points) in different coordinates systems, importing contours in an area with any shape specified. It can also be used for preliminary volume calculation, to export objects from AutoCAD to visualize them inside Google Earth or doing the opposite (that is, importing a Google Earth KML file).