Renewable Energy World - magazine

Подождите немного. Документ загружается.

LARGE SCALE SOLAR SUPPLEMENT - MAY 2011

manufacturer SEPSA, which is concentrated on providing solar farm-

scale inverters. While this could increase how well these companies

serve their chosen segment, it will also make it harder for them to reduce

their costs. Also included in this class are those which have limited their

market geographically. For example, some Japanese companies have

decided to focus on their local market rather than tackle the challenge

of decreasing their costs to enter more competitive markets.

The remaining two classes are aggressively seeking to reduce their

manufacturing costs, and can be distinguished by exactly how they

seek to do this. The rst approach, extensive automation, is typied

by industry-leading German inverter specialist SMA Solar Technology.

‘SMA decided to automate, especially for the residential and small

commercial product portfolio,’ said Le Gouic. ‘There are actually very

few people in the facility. It’s advantageous for them, because PV

inverters, especially when they are very big, need lots of people for

assembly, testing and cleaning. By reducing the manpower needed at

each process step, such companies can successfully reduce costs.’

The nal inverter manufacturer class is made up of companies

establishing facilities in countries where labour costs are low, particularly

eastern Europe and China. With the European market still driving today’s

PV industry, such companies also frequently seek suitable contract

manufacturing partners in eastern Europe. Even Chinese players need

to be physically present where the demand for solar power-generating

technology is strong, so they have also been seeking local sales channels

and local distribution in Europe.

Payback time

These strategies have been developed largely as manufacturers

recognise PV inverters must be considered from the overall perspective

of electricity generation economics. ‘People don’t think “I want the

most efcient inverter”, “the cheapest inverter” or “the most reliable

inverter” any more,’ said Le Gouic. ‘People think “I want the quickest

return on investment time; whatever I invest, I get my payback as soon as

possible and then generate some cash”.’ This kind of thinking considers

a PV installation overall, balancing initial cost against overall revenue

and therefore total electrical output. Consequently, while fundamentals

like reliability, efciency and price remain important, PV inverters have

increasingly had to accommodate the specic challenges of generating

electricity from solar energy.

‘At the inverter level this means that manufacturers integrate

functionalities, like monitoring and efcient maximum power point

tracking (MPPT),’ he said. The rst embodiments of MPPT developed

were motorised tracking systems that follow the sun, typically used at

the utility scale.

While inverter manufacturers’ efciency expertise can minimise the

energy this movement consumes, MPPT increasingly exploits software

technology that can be deployed in all market segments. In these cases,

algorithms adapt circuit congurations to ensure maximum harvest is

maintained in the presence of complications like passing clouds, rain,

dust, wind and leaves falling on the panels.

To truly keep a system at its maximum power point, an MPPT

system should respond to these events immediately, although

this is difcult to achieve. ‘The faster and more accurate your MPPT is,

the better,’ he said.

Anti-theft and anti-re solutions, which rapidly communicate

changes in power output arising from such incidents, are two other

kinds of monitoring that inverters are increasingly incorporating. At the

residential level, microinverters are attracting a great deal of attention

in the US as a way homeowners can monitor their panels. These allow

users to access data on how much energy they have generated through

a web portal. ‘It looks great, but the technology is much more expensive.

They are twice or 2.5 times the price of a standard inverter,’ he added.

California-based Enphase is the leading exponent of microinverters. It is

now hoping to push its products in Europe, although Le Gouic expects

it will need to accommodate the strength of the cost driver in that

market to succeed.

ADDITIONAL TECHNOLOGIES ADOPTED

BY MANUFACTURERS TO DIFFERENTIATE

THEMSELVES ARE NOW WIDESPREAD

While these additional technologies were initially adopted by

inverter manufacturers to differentiate themselves from each other they

are now becoming so widespread that they are almost standard. Yole

Développement estimates that more than 95% of inverter producers

now integrate such capabilities. ‘It’s very important as functionality, but

it’s also a marketing and commercial tool,’ said Le Gouic.

Individuality remains

Yet even as some common themes have developed in the PV industry,

many product features are still non-standard. ‘Engineering, procurement

and construction (EPC) contractors, integrators and installers say that

they are not asking for regular types of products for installation,’ he

said. One reason for this heterogeneity is that the standards for

connecting to electricity grids differ from country to country, obliging

companies to offer inverters to t each specication. The fact that each

company’s inverters are distinct from each other has also made them

less interchangeable. This means that major solar projects will only use

one company’s inverters, whereas just a few years ago there was more

scope for using multiple suppliers.

The number of inverter suppliers that have subsequently emerged

became especially useful during 2010, when some were hit by

shortages. Then, manufacturers of semiconductor devices and some

other component manufacturers were unable to meet the demand

from inverter makers. A simultaneous surge in orders rapidly created

a six-month lead time for inverter deliveries from many suppliers. Their

customers understandably turned to whichever manufacturer could

supply them rst, although in Europe keeping price to a minimum also

remained equally important.

One Chinese manufacturer in particular – Sungrow – was able to satisfy

both these needs and consequently penetrate the European market when

they might not otherwise have been able to. ‘They have a large power

range product portfolio, so they can cover any type of installation, plus

they are very cost competitive,’ said Le Gouic. ‘They beneted from this

shortage situation, starting dialogues with EPC contractors or integrators.

Now they have their network. A large amount of the money they have

they inject into R&D in China, it’s really very impressive.’ Power-One,

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

LARGE SCALE SOLAR SUPPLEMENT - MAY 2011

based in Camarillo, California, was another beneciary of the shortages,

Yole Développement believes.

While minimising costs is necessary for PV to be competitive with

other power generation technologies, this desire can also lead to some

inconvenient compromises. This can be seen with input capacitors,

components that have a key role to play in an inverter’s reliability,

as they are typically the rst to fail. For Chinese companies, input

capacitors typically have a ve-year lifetime, said Le Gouic. ‘To reduce

cost, those companies don’t want to change that,’ he said. Instead, they

provide ve- or 10-year warranties that allow one replacement, in order

to continue with the low cost capacitors. Inverters made elsewhere in

the world are more reliable, with input capacitors used by Japanese

companies lasting for up to 20 years, but customers must pay more for

that reliability.

Rather than only addressing the upfront costs of their components

like this, in other areas the inverter industry is pursuing component

innovations that demand a more holistic payback perspective. ‘People

are considering moving to compound semiconductor components –

especially diodes, and now transistors,’ said Le Gouic. Gallium nitride

(GaN) and silicon carbide (SiC) compound semiconductor devices offer

higher efciency than their silicon rivals, at a price. In large inverters the

overall cost difference is slight, meaning that this is where the improved

efciency is most likely to have a positive impact.

Such devices are still in their infancy, however, and widely considered

too expensive. Among the best established are SiC diodes produced by

German electronic giant Inneon, with transistors still in the early stages

of commercialisation. Le Gouic indicates that PV inverter producers are

already working with SiC and GaN transistors, although it’s still too early

to say which products will be adopted, if any. ‘We know that leading

companies are asking for both in looking for higher efciency,’ he

said. Ultimately, any choice between the two could be driven by the

automotive industry, which uses inverters with the same power range. If

it adopts one semiconductor material as standard, PV inverters will likely

follow their lead.

Storm forecast

It is therefore clear that PV inverter manufacturers want to lower their

costs, whether it be by adopting strategies emerging across the

industry, or through more individual efforts. The ultimate goal must be

to take a greater share of what Yole Développement estimated was a

€3.3 billion PV inverter market in 2010. Underlying this competition is

the need to reduce PV system costs generally. Even though reduced

silicon prices are set to provide the majority of this, with inverters

typically worth less than 10% of a system’s installation cost, there is still

a desire for cheaper inverters.

As a result, European customers are reluctant to accept inverter

prices above €0.24/W, which is a problem for Japanese vendors offering

products at €0.25/W, by Yole Développement’s estimates. However,

Japanese producers have recently been focusing on penetrating the

European market with their high-quality, reliable solutions with greater

vigour than ever. While cost is not their strength, these companies are

concentrating on closely tailoring their offerings to individual national

markets, and Yole expects that they will have some success. Meanwhile,

despite poor reliability, Chinese PV inverter makers lead the industry

for cost at €0.19/W–€0.20/W, Yole believes. US and EU manufacturers

provide systems that offer both reliability and price in between these

extremes, at €0.22/W and €0.20/W–€0.21/W respectively.

With inverter suppliers having just recovered from one set of

shortages, hopes of price reductions were dealt an unwelcome

blow by the Japanese earthquake and tsunami in March 2011. The

country’s electronics manufacturers make a wide range of small inverter

components, such as microcontroller units and transistor drivers. ‘They

supply Chinese, Japanese, Korean or even German manufacturers –

and I believe some of their fabs have been affected,’ Le Gouic said. ‘I

think this will have some consequences.’ Against this background, Yole

predicts little progress on costs, with prices from Chinese producers

unlikely to be matched in Europe for three to four years.

But such predictions are difcult, said Le Gouic, with perhaps an

even greater upheaval on its way than the past 18 months have seen.

‘China is really problematic,’ he said, ‘because the Chinese government

is helping manufacturers.’ The existing prices Yole Développement

quotes do not take this into account, the analyst added. ‘The Chinese

government has a list of companies it wants to help and support so they

can enter the European market with low-cost products. The target is

€0.06–€0.08. That’s dramatically low and people will get upset with this.

It’s very dangerous.’ The PV inverter industry could see trade disputes,

said Le Gouic. ‘I think this may lead to quotas for Chinese products in

Europe or even the US,’ he warned.

Author Details

Andy Extance is a freelance journalist based in the UK.

e-mail: rew@pennwell.com

This article is available on-line. To comment on it or forward it to

a colleague, visit: www.RenewableEnergyWorld.com

Inverter manufacturers are facing cost challenges Sputnik Engineering

INVERTER COST STRATEGIES

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

Crédits photos : Corbis - aressy.com

Change for more energy efficiency?

Naturally.

Intersolar Europe

Munich, June 9-11, 2010

Hall.Stand B4.158

AC500 Programmable Logic Controller

Soaring energy prices and concern about climate change from man-made emissions

of carbon dioxide have propelled energy efficiency to the top of the agenda in the

boardroom, in public debate and global policy. ABB’s energy efficient products,

systems, solutions and services help customers produce and deliver more goods

and power for each unit of energy they use. The AC500 PLC optimizes energy

consumption to support sustainable energy growth which can significantly reduce

your energy costs. Choose efficiency and performance with AC500, your PLC from

ABB. www.abb.com/plc

➤ Learn more about our PLC solutions for the solar industry!

Mail your local PLC contact

www.abb.com/plc

For more info, enter 63 at rew.hotims.com

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

_______________

_______

_________

_____

LARGE SCALE SOLAR SUPPLEMENT - MAY 2011

PROJECT PROFILE

By David Appleyard

SAN DIEGO’S NEW

CPV SOLAR GIANT

The development of a commerical large-scale CPV project is helping to establish the performance credentials of a

technology that offers signicant opportunities at the power plant scale. With a 150 MW project planned in San Diego and a

25-year PPA in place, CPV has at last entered the commercial arena.

CPV TECHNOLOGY HITTING BIG TIME

Standing in the New Mexico desert, a 1 MW Concentrating

Photovoltaic (CPV) power plant is establishing a route for the

emergence of this utility-scale technology. Installation of this rst pilot

commercial deployment began in the summer of 2010 and the plant

was commissioned early in 2011, with ofcial inauguration in April.

Located on the tailings site of Chevron Mining Inc’s (CMI)

molybdenum mine in Questa, New Mexico, some 2000 metres above

sea level in an area of the US noted for its high levels of Direct Normal

Irradiance (DNI), its developers say the project will demonstrate the

technology as well as a practical use of previously impacted land.

Electricity produced from the installation will be sold to the Kit Carson

Electric Cooperative, through a power purchase agreement.

Covering some 20 acres (8 ha) the site has 173 CPV modules,

each of which has an area of about 18 by 21 feet (35 m

) and is pole

mounted on dual axis trackers supplied by a major manufacturer. The

Concentrix technology uses Fresnel lenses to concentrate sunlight

almost 500 times onto high efciency multi-junction PV cells. With

this technology, Soitec claims to achieve AC system efciencies

of 25% and more, signicantly higher than currently available

conventional solar PV technology, and as a result, cost reductions

of 10%–20% could be reached, depending on the location of the

installation, it says.

Hansjoerg Lerchenmueller, founder of Concentrix and now senior

VP Customer Group at Soitec, explains to REW that the system uses

a relatively simple architecture, with a Fresnel lens and no secondary

optics, and while this does make for ease of manufacture, it also

implies a low acceptance angle, hence the need for extremely accurate

tracking. Lerchenmueller adds that by developing the inverter system

too, in a single unit the company has combined the three functions of

DC/AC conversion; tracker control, in which the system achieves very

Chevron’s molybdenum mine tailings site in New Mexico offers an ideal climate for CPV generation

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

LARGE SCALE SOLAR SUPPLEMENT - MAY 2011

high accuracy using system output as a controlling input; and output

monitoring, remotely or otherwise.

‘The “sweet spot” for CPV is really 20–200 MW, where there is a

real commercial gain’ says Lerchenmueller, adding that the Chevron

plant is a ‘very, very important milestone’. ‘This is a real power plant,’

he says. ‘We have been installing power plants since 2008 and

we are making tremendous progress both in terms of power plant

efciency and installation time, which fell dramatically with the 170-

unit system.’

Through 2008 and 2009 the company had installed systems in

Seville and Puertollano, Spain, of 100, 200 and 300 kW, he adds. In

2010 the company installed overall close to 2 MW of capacity with

projects or demo installations in more than 10 countries including the

US, Spain, South Africa, Italy, Egypt, Jordan and France. ‘We have

demonstrable longevity on the eld, with three years’ experience

and no evidence of performance degradation in that time,’ says

Lerchenmueller, adding that the modules have an anticipated 25-

year operational lifespan. ‘We’re really at the point where we can

take off at the real power plant level,’ he concludes. Soitec achieved

International Electrotechnical Commission (IEC) certication 62108

for its CX-75 module in January 2010.

Large scale development

With the project at Questa underway, and perhaps more signicant in

terms of the roll-out of the technology, Soitec also recently announced

that its CPV technology had been selected by Tenaska Solar Ventures

for a 150 MW power plant near San Diego, California.

Imperial Solar Energy Center (ISEC) West will be constructed on

a 1057 acre (427 ha) site in Southern California’s western Imperial

County. Delivery of the CPV systems to the ISEC West plant is due to

begin in early 2013 and is expected to be completed in 2015.

Furthermore, to support the project, Soitec revealed plans to

build a new manufacturing facility in the region that will be able to

produce some 200 MW of modules annually once fully ramped up.

Modules from this factory will be used to supply ISEC West as well as

other utility-scale solar power projects throughout the Southwest US

and elsewhere. The factory location is anticipated to be announced

in summer 2011, with completion expected within 18 months of the

start of construction. Currently, Soitec operates a fully automated

industrial production line for Concentrix technology modules with an

annual production capacity of 25 MW, located in Freiburg, Germany.

Utility group San Diego Gas & Electric (SDG&E) has already

signed a 25-year power-purchase agreement with a subsidiary of

CSOLAR Development, LLC, a renewable energy company managed

by Tenaska Solar Ventures that will develop and operate the plant, for

the output from the ISEC West plant.

Commenting on the development of local transmission

infrastructure and its impact on renewable energy projects

in the region, James Avery, SDG&E’s senior vice president of

power supply, said: ‘The start of construction of the Sunrise Powerlink

has triggered a wave of proposed new utility-scale solar and wind

projects in the Imperial Valley region.’

The ISEC West project has applied for a US DOE loan guarantee.

Upon receipt of the guarantee and closing of its agreement with

Tenaska, Soitec will implement capacity investments to construct its

San Diego area factory and pursue options for related nancing, it

says in a statement.

In April 2011, SDG&E announced the signing of three further

contracts with Soitec for CPV power plants with a combined capacity

of 30 MW. As with ISEC West, the modules will again be manufactured

in the new factory. Soitec’s delivery of the CPV systems for these three

new solar energy facilities in San Diego County will begin in 2013

and nish in 2014, given relevant approvals from the California Public

Utilities Commission. No loan guarantee is required for these projects.

THE SUNRISE POWERLINK HAS

TRIGGERED A WAVE OF PROPOSED NEW

UTILITY-SCALE SOLAR PROJECTS

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

LARGE SCALE SOLAR SUPPLEMENT - MAY 2011

Dave Fiorelli, president of Tenaska’s Development Group,

adds: ‘The ISEC West solar power plant will demonstrate

Concentrix CPV scalability, and commercial viability of this

innovative technology for utility scale deployment.’

CPV’s geographical advantage

CPV systems are typically more efcient than conventional

solar systems at locations with both high ambient

temperatures and dry weather conditions. Because of the

very low temperature coefcient of its solar cells, a CPV

system’s performance is much less affected by temperature

than other photovoltaic technologies. Another key

advantage of CPV technology is the very low levels of water

required for operations, essentially used in cleaning only, a

crucial consideration for the water-constrained regions to

which it is suited, such as the Imperial Valley, which is some

150 miles (230 km) from the coast. Indeed, such technology

is expected to work best in areas with higher DNI like

northern New Mexico and southern California, as well as

in north and southern Africa, the Middle East, and much

of China and India. Certainly, in 2010 Soitec announced

that it had joined the Desertec Industrial Initiative (Dii)

as Associated Partner and Medgrid as a founding member, in the

expectation that the decision will pave the way to utility-scale CPV

projects in the Middle East and North Africa (MENA).

Soitec, which produces high-performance materials for the

semiconductor industry, including substrates for SOI (Silicon-on-

Insulator) and CPV systems, among other applications, acquired

Concentrix Solar GmbH in late 2009, valuing the company at some

€55 million. With the acquisition of Concentrix Solar, originally a

2005 spinout from the Fraunhofer ISE, Soitec also signed a strategic

technology alliance with both the Fraunhofer ISE and the research

institute CEA-Leti. This agreement included a long-term licence

agreement related to the manufacturing of concentrator cells. They

plan to jointly develop the next generation of very high efciency CPV

solar cells based on Soitec’s proprietary technologies, signicantly

improving CPV system performance.

Lerchenmueller explains the company’s push to improve efciency

with Soitec’s Smart Cut technology. ‘By peeling off thin layers of

semiconductor materials and mechanical stacking of the layers we are

less restricted in the selection of the semiconductor materials and get

to less defects,’ he says. ‘We have 28% module efciency currently

and expect to achieve 30% this year, and more still in coming years.

On the cell level we are aiming for 50%.’

In October last year, Soitec also concluded a global alliance with

Johnson Controls for the development and construction of utility-

scale solar energy facilities. Under the terms of the alliance, Johnson

Controls will build, operate, maintain and provide lifecycle support

for solar installations using Concentrix CPV technology.

Lerchenmueller sums up: ‘The key future market is utility-scale,

not MW- but GW-scale. We’re going to need a lot of inexpensive

renewable energy over the coming years. To achieve that we need to

go to where there is lots of sun and we need to go for big economies

of scale.’ He estimates this ‘sweet spot’ will be a market worth some

$2 billion annually.

Author Details

David Appleyard is chief editor of Renewable Energy World

magazine.

e-mail: rew@pennwell.com

This article is available on-line. To comment on it or forward it to a

colleague, visit: www.RenewableEnergyWorld.com

CPV SYSTEMS ARE TYPICALLY MORE

EFFICIENT AT LOCATIONS WITH HIGH

AMBIENT TEMPERATURES

Concentrix CPV modules at the 1 MW Questa installation Chevron

PROJECT PROFILE

ABB FRANCE 17

ABB OY IFC

HUBER SUHNER AG 4

RAYCAP S.A. 13

SCHOTT AG PV OBC

SPUTNIK ENGINEERING IBC

WESTINGHOUSE SOLAR 11

ZIGOR CORPORACIÓN SA 5

ADVERTISERS’ INDEX

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

A properly matured Swiss product.

SolarMax inverters are made to deliver full capacity and a clever

cooling system helps them keep their cool at all times. And that

is good for you. Because maximum efficiency and the very best

reliability give you both the best-possible yields and a carefree

life as well.

And that is no surprise because every SolarMax is a genuinely

Swiss product with typical Swiss virtues: Highest quality materials,

no compromises in their fabrication, and a generous warranty

whose benets you will probably never need anyway. And if you do,

our After Sales Service will respond quickly and reliably.

Whether you are planning a PV system for a single-family home or

a large solar power plant: SolarMax has the right product for you.

Nothing cheesy about that.

Easy

installation

Swiss Quality

Competent

After Sales

Service

Maximum

reliability

High, constant

efciency

Maximum

revenues

Sputnik Engineering AG

Höheweg 85

CH-2502 Biel/Bienne

Switzerland

Tel: +41 32 346 56 00

info@solarmax.com

www.solarmax.com

Maximise

your yield!

For more info, enter 05 at rew.hotims.com

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

___________

_______

Sun in, electricity out.

If only everything in the future

could be so predictable.

* In a long-term study conducted by the Fraunhofer-

Institute the SCHOTT Solar modules still achieved over

90% of their original performance even after 25 years.

Solar modules from SCHOTT Solar have what it takes for long-term attractive

revenues: high performance stability*, the quality of a renowned German

technology company and experience in

solar technology since 1958.

More information at

schottsolar.com/solar-yield

INCREDIBLY STABLE FORECAST.

For more info, enter 04 at rew.hotims.com

RENEWABLE

ENERGY

WORLD

RENEWABLE

ENERGY

WORLD

____________________

_______

Renewable Energy World - magazine - 5/6-2011

Подождите немного. Документ загружается.