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UL Approval for Micro Inverters

Enecsys solar PV micro inverter becomes the world’s first without electrolytic capacitors to gain U. S. certification to UL1741 standard

Cambridge, U. K., January 8, 2011: Enecsys Limited, a solar PV micro inverter company, has announced UL1741 certification for its products. The patented design of the Enecsys micro inverter uses a rugged topology that eliminates electrolytic capacitors and opto-couplers, components that limit operating life and compromise reliability. Enecsys 240W micro inverters are the first micro inverters without electrolytic capacitors to achieve UL1741 certification. The same product is also certified for use in Europe, making Enecsys is the first company to introduce a truly global solar PV micro inverter. The inverter has an operating life expectancy of greater than 25 years, matching that of solar PV modules. This transforms the economic model of solar PV systems through greatly enhanced system reliability, energy harvest, ease of installation and improved system safety.

Solar PV systems based on micro inverters harvest from 5 to 20% more energy over the life of the system, compared to traditional string inverter based systems. In a micro-inverter based system Maximum Power Point Tracking (MPPT) is performed on each solar module and thus maximizing energy harvest even under partial shading, module mismatch or obstructions from leaves or debris. Systems are simpler to design and install and are safer because the high-voltage DC present in conventional solar PV installations is not present. No string inverter is needed because the DC output of each solar module is converted to AC using a micro-inverter mounted on the rack behind each module. This eliminates the central point-of-failure and the primary failure mechanism found in traditional inverters systems and micro inverters currently available in the market.

The reliability of Enecsys micro inverters has been verified using HALT, HASS and accelerated life tests to IEC61215, the same methodology used to test solar PV modules. The micro-inverters maintain full performance from -40 degrees C to +85 degrees C, ensuring efficient operation in real-world conditions. The Enecsys Wireless Monitoring System provides real time performance information for each solar module in order to maintain the high performance of the solar PV system throughout the operating lifetime.

The Enecsys micro inverter is designed to operate in both North American (60Hz) and European (50Hz) electricity grid systems. The micro inverters are safety and EMC evaluated to EN 62109, UL1741, TUV and CE. Country-specific requirements, including VDE V 0126-1: 2006 compliance, are achieved through the use of specific Enecsys installation products.

Using Home Power for Hedging Yourself in Two Ways

The beauty of a play in residential-scale Green Energy is its capability of hedging against both a general economic downturn and an increase in electricity prices at one go. Both are likely to happen rather soon (and yes, even though it may sound contradictory from a conventional economic point of view to have both a severe recession or even deflation and an increase in energy prices at roughly the same time, this is still a very likely scenario). The supporting fundamentals for both are in place, it’s just a matter of time for them to materialize.

Click here to read more…

Increasing Micro Generation Output: On-Board Micro Inverters

Micro inverters are a very innovative apporach to deploying truly modular solar PV systems.

A number of different micro inverter models have been developed lately, largely based on an innovation originating at Cambridge University and commercially developed by Enecsys. The Involar M-250 micro inverter is another implementation based on this concept, and while there is a certain smell to it, we are reporting on that latter product here. All micro inverters convert DC collected from a single solar panel or two into AC, tie PV modules together using AC connections rather than expensive and highly resistant DC connections, later transport the generated power to the grid, and usually also include components for monitoring power generation data. On top of the Involar M-250, we also offer the European-made Enecsys quality micro inverter models ranging from 200 Watts to 480 Watts and will add U. S. quality inverters in the near future. Enecsys inverters are fully UL-approved for the U. S. and Canada with the European models CE, UK G-83, German VDE 0126-1-1 certified.

The micro inverter concept has been developed in the U. K. by Cambridge University and launched to the market by Enecsys, Cambridge-based engineering firm


The following is quoted (and slightly polished) from the Chinese producer’s description:

A schmeatic overview of a micro inverter setup

The following steps elucidate the basic working princilples behind the INVOLAR micro inverter:

Step One

Solar photovoltaic modules convert light energy to direct current through the photoelectric effect.

Step Two

Micro inverters attached to photovoltaic modules finish the DC-AC conversion process.

Step Three

Synchronize and transport energy to the grid through phase-lock technologies with speed and precision.

Remark 1:Independent modules supported by micro inverters (250W) could form a parallel connection for a larger power requirement
Remark 2:MIS =Micro Inverter System

Features of the M250 Microinverter

      * Maximizes energy harvest – Different from conventional centralized inverters, M250 micro inverters conduct per-module MPPT, maximizing the efficiency of each single module with a consequent 25% increase in energy harvest.


      * Applicable to various conditions – M250 micro inverters allow for mismatch of photovoltaic modules, and each module can make flexible reactions to obstruction shading, inter-row shading, and obstacles such as dust or debris to avoid a sharp decrease in system efficiency.


      * Improved safety – With the built-in DC-AC conversion function, M250 micro inverters avoid dangerous HV DC circuits necessary to photovoltaic systems supported by conventional centralized inverters.


      * Fast problem diagnosis & solution – With PLC (Power Line Communications, i e electricity network) or WiFi technology, it is convenient to maintain real-time monitoring of every single module in the photovoltaic system.


      * Low failure rate – M250 micro inverter’s distributed framework ensures no single point of failure that would result in bringing the whole system down.


      * Plug-and-play installation – Free from the HV DC circuit, photovoltaic systems supported by M250 micro inverters could have fast, easy, and safe installation by allowing for PV module mismatch, a 15-25% decrease of installation time and cost, and flexibility in the changing of systems.


      * excellent INVOLAR M250 micro inverter is the result of the technical design with a high efficiency in its standard of air power supply, high power density, and high reliability.


      * By making use of the resonance soft-switching technology in MAC250 micro inverter’s main circuit, the switch frequency reaches near thousands of kHz, reducing wear and tear of the switch.


      * small, lightweight, high frequency transformer that achieves electrical isolation, power conversion, and high power density.


    * intrinsically safe current source hardware topology and high reliability.

Micro inverter technology by INVOLAR has resulted in a revolutionary device that is fully integrated into each individual module, converting DC to AC at the module level, with an independent MPPT function. INVOLAR’s micro-inverters outperform centralized inverters in:

1. Module-level Maximum Power Point Tracking (MPPT)

Different from the conventional centralized PV inverter, the microinverter enables each individual module to achieve MPPT, which allows for module mismatches and can harvest more solar power.

2. Increased Efficiency during the System’s Life Cycle

With the microinverter technology, the photovoltaic system receives a dramatically higher power output, more than 25% additional energy harvest in a less-than-ideal environment with possible obstruction shading, inter-row shading, and obstacles such as dust or debris.

3.Intelligence and Reliability

With the distributed microinverter framework, there is no single point of failure, which means that failure of any module will only affect its own performance and will NOT affect the other modules’ performances.

Involar’s unique Power Line Communication (PLC) and internet technologies enable real-time monitoring of every single module in the photovoltaic system for fast diagnosis and solution to a problem, thus improve reliability and system uptime.

We recommend switching off the integrated WiFi transmitters and use powerline communications instead in order to avoid potentially harmful EMF exposure; shield powerlines if necessary in order to insulate against powerline-transmitted high frequency signals. The full set of monitoring features is still available when using the less hazardous PLC and cable-Ethernet data transmission.

The INVOLAR remote monitoring system is based on a so-called ETU which is in effect a piggy-back box containing a data transmission unit. This unit is locked to transmit data to the manufacturer’s central data base on a proprietary protocol using internet protocol (high port 7001). If micro inverter user employs any sort of meaningful firewalling policy (blocking transmissions from the inside over non-standard ports) or if you just feel uneasy (actually, we do somehow…) to send your private solar energy data to some black box located in China and Chinese-controlled, you may want to use the “naked” micro inverter or multiple micro inverter units only.

Internet usage directives and Netiquette require every internet user to save bandwith and not flood the network or cause any jams by unnecessary usage. Transmitting a continuous data stream all the way to China is not exactly in line with proper internet use or common sense.

INVOLAR micro inverters can as well be run, and their other technical advantages such as increased output per panel can be used, without remote monitoring and without the “ETU” add-on. In order to lower installation cost — and in light of the above security considerations — you might be well-advised or simply want to go for such a bare-bones solution.

We do provide both solutions as an option, but feel it is our duty to be fair and raise the issue above for everyone to decide for themselves. In a simple consumer or Home Power setting the above issue may be less significant.

With or without the ETU the Involar M250 micro inverter enhances both modularity and configurability of solar PV arrays and, by eliminating DC line resistance, increase performance per solar panel up to 25%. Using a micro inverter, both accessory unit cost and maintenance cost can be decreased significantly in solar PV systems.

Micro inverters may also be used with micro wind turbines and is suitable for models from 50 W up to approx 1000 W rated power (depending on actual local wind conditions) when connected to a suitable regulator (or diversion or dump load). The Involar M250 along with the high-quality U. K.-manufactured Enecsys micro inverters are currently undergoing tests with LE-v50, LE-300 and the Airdolphin DC turbines.

Very Powerful CSP Generator

We are glad to announce a novel CSP generator unit that is both extremely powerful and small in size. Using Concentrating Solar Power, the SopoLite™ unit generates heat for both power generation or direct heat applications (hot water, air conditioning/refrigeration, process heat). The SopoLite™ system is available as a part of the Mini Wind & Solar Technologies program by ecoPen Ltd.

SopoLite™ can be adapted to Home Power applications and is suitable for larger-scale power generation including commercial process heat and electricity generation using thermal engines. Sopogy trough technology can be configured to replace natural gas or other fossil power plants and significantly reduce carbon emmissions.

SopoLite, available shortly through Mini Wind & Solar Technologies by ecoPen Ltd



The system consists of a scaled down version of Sopogy’s parabolic trough that is able to follow the sun from east to west during the course of the day. As in a typical solar field, a mineral oil circulating through the system gains temperature as the parabolic trough is focused at the sun with a proprietary tracking system. The heat generated in this fashion is typically used for electricity generation, air conditioning and process heat applications. On the SopoLite™, various sensors measure the temperature gain, the flow velocities, solar irradiance, wind speed, rainfall and ambient temperature. These parameters are used to determine the thermal output of the collectors. The sophisticated controls allow remote access to evaluate all relevant data through an interactive graphic interface.

SopoLite, available shortly through Mini Wind & Solar Technologies by ecoPen Ltd



Pre-configured SopoLite™ systems are able to cover larger and commercial energy needs and are priced around £49,600.00 in the U. K. or roughly €54,800.00 in Eurozone and other EEC countries. Although residential-scale or small business systems can be deployed, SopoLite™ systems are tailoured for and primarily focused towards larger-scale residential developments, real estate management, commercial energy users and businesses who want to green their operations and significantly cut on high energy cost.

SopoLite, available shortly through Mini Wind & Solar Technologies by ecoPen Ltd


In the U. K., SopoLite™ systems are expected to be eligible for payments of 18.6p per KWh equivalent generated under the MCS Solar Thermal scheme (green energy cashback).

For further details, to discuss system requirements or to receive a no-obligation quote for an individual project, please contact us using the Reply field below.

Get Some German Engineering (Not Just for Your Driveway)

A revolutionary design, patented blades and an extremely high output ratio — these are the main features of a micro wind turbine truly “Made in Germany” but without the associated cost of most of the VW models people put in their driveways these days.

The BreezeBreaker 500 is under 5 ft (1.5 m) in diameter and costs under $1500. Developed by a 19-year old inventor from Hannover, Germany, this turbine has the lowest weight-to-output ratio in the world and undercuts Japan’s Zephyr Airdolphin Z1000-25 and Airdolphin GTO™ “next generation” models by roughly one third.

It did not take very long for the “next generation” to start looking like a rather old one: BreezeBreaker 500 by 19 years old Fritz Unger does not only sport a sensational weight-to-output ratio (just 11.875 grams per Watt of rated power) but also makes clever use of rotor physics: 2-blade designs are generally far superior to more blades as 2-blade rotors reduce blade turbulence and suffer significantly less wind energy loss.

Interested? Leave a reply below or e-mail, and we will get back to you with full manufacturer details.

You Need to “Fly” a Mini Wind Turbine

Fancy a mini wind turbine? Like to save a bundle on energy cost or even make money by “selling” back — that is, export or feed-out electricity– to the grid? Sounds good?

Well it is — unless you get tricked into buying one of those attrative, cheap, and too-good-to-be-true junk turbines or dream up the impossible. Both are going to not work and will only cost you money. They will also give mini wind turbines or Home Power in general a bad name. Educate yourself before you buy! Be aware of the physical constaints and don’t ever assume that it might be possible to spin some little wheel from China up on your roof for a few hundred bucks or so. Never ever assume to even make lots of money from a junk turbine either.

It is just not that easy.

There’s no such thing as a free lunch, this applies as much to Home Power generation as to any other area this phrase has been coined for. Do not believe any adverts touting cheap or apparently “affordable” products that will cover all your electricity needs or even promise you to effortlessly cash in big on “excess energy” exported to the grid. If it sounds “too good to be true”, it usually is. If it promises spectacular percentage returns, slash a few zeros. Don’t overestimate the potential of Home Power. Don’t expect to get rich quick, get rid of all your worries or make a lot of money with your mini wind turbine.

This does not mean it can’t be done — you need to know what you’re doing though, and you just won’t get it for “cheap”.

First of all, you need to live in a suitable location or at least have a chance to set up a proper tower for your mini wind project. Not all kinds of “wind” are suitable just because you can feel it in your face. The energy that can be harvested from the wind is better in “clean” wind situations. Buildings, trees and terrain shape may slow down the wind or cause turbulence. Slow wind, obviously, decreases potential energy output and may “cost” you some of your return. Turbulences do the same but also cause additional stress on the turbine, decrease its lifetime and, that way, may cost you even more. Overly simplified and as a rule of thumb, a mini wind turbine needs to sit about 30 feet above any obstacle within a 300 feet range. To get good results, a 40 foot tower would be needed in most areas. Unless for very special tubine designs or in a particularly suitable spot, roof-top deployment is not suitable.

This is why people say “flying” a mini wind turbine.

Flying is expensive — this also applies to flying your mini wind turbine. A suitable tower may very well cost as much as the turbine itself. Still, this is a good investment as it would be a waste of money to use a tower that is too low: if feeding-out electricity to the grid is your objective, this would be uneconomical and unnecessarily prolong the payback period of your equipment or make your mini wind project inefficient by design.

The bottom line is: never buy any garbage turbine from China or your average sweat-shop economy across the ocean, over, or eBay or you’ll lose money. Never use a tower that is too low or you’ll lose a good part of your profits (or the chance to make any profits at all). You don’t find suitable turbines in a local garden center either. Educate yourself before you spend any serious money, read a few books and know what you are doing before you buy your equipment. If you do it right, you may be able to make some money or even come up with very decent returns percentagewise. The key is doing your homework and knowing your numbers (which includes doing a proper wind survey). Then, Mini Wind may indeed turn out to be what you always were looking for.

Door Now Open for Feed-In Tariffs in the U. S.

The U. S. Federal Energy Regulatory Commission has ruled that U. S. states are free to enact their own feed-in tariff policies. This effectively clears the way for Feed-In Tariffs in the U. S. at state level similar to the ones in Germany or in the Province of Ontario. This decision by the chief regulatory body is expected to provide a further boost to Home Power and Renewable Energy as a whole on top of the already positive sentiment among U. S. consumers.

Latest polls show that up to 91% of consumers are in favor of Home Power generation and would be interested to set up their own systems sooner rather than later. The U. S. small wind energy sector has already experienced a 15% annual growth over the last years and is expected to accelerate even further. Equally bright are the prospects for Solar Power with improved technologies in solar thermal and CSP (concentrated solar power) as well as PV (photovoltaic or solar electric) generation.

Using Home Power for Hedging Yourself in Two Ways

The beauty of a Play in Residential-Scale Green Energy is its capability of hedging you against both a general economic downturn and an increase in electricity prices at one go. Both are likely to happen rather soon (and yes, even though it may sound contradictory from a conventional economic point of view to have both a severe recession or even deflation and an increase in energy prices at roughly the same time, this is still a very likely scenario). The supporting fundamentals for both are in place, it’s just a matter of time for them to materialize.

Click here to read more…

Can Airdolphin Power My Home?

Some of the most frequently-asked questions we receive is how much power to expect from mini wind turbines and if they can supplement in a meaningful way or even fully power an average home.

A very brief overview on what to expect in a real-life setting from a small wind turbine and how to expand energy output in a domestic setting.

This PDF leaflet is part of the downloadable information we provide free to registered website users.

Mini Wind + Solar = Perfect Home Power Mix

For both small and larger applications, miniwind and solar go nicely together in hybrid systems and help building the perfect Home Power mix of Clean and Green Energy. What matters is that it’s Renewable and Low Impact — both visually and overall-environmentally!