Our Technology

Tigo Energy Maximizer

Tigo Energy’s technology delivers more energy, active management, and more reliability for utility, commercial, and residential solar installations. This results in a faster return on investment and lower cost of ownership. Tigo Energy’s revolutionary solution addresses a number of issues that limit the efficiency, availability and flexibility of today’s solar installations.

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Figure 1. – The Tigo Energy Maximizer

More Energy

Today’s best installations are designed to maximize power output across the entire system. An array, however, is limited by the weakest panel in a string and individual panel performance can vary dramatically. Even a system architected to avoid shade can be affected by dust & debris, temperature and degradation over time. These environmental issues can create as much as a 15% mismatch between the best and worst performing panels in a typical string.

Tigo Energy has introduced the Tigo Energy™ Maximizer System which maximizes the output of each panel, harvesting power that is simply wasted today. Furthermore, the localized Maximum Power Point Tracking (MPPT) is accomplished with unprecedented accuracy and efficiency. For utility scale and commercial projects, the Tigo Energy™ Maximizer System can return up to 8% incremental energy output. In residential systems which often encounter shading, the revolutionary solution can improve energy output in excess of 20%.

The Tigo Energy solution places very simple electronics at the panel (the Tigo Energy™ Module Maximizer) along with a highly-intelligent Tigo Energy Maximizer Management Unit (MMU) to distribute the MPPT function. The Tigo Energy Module Maximizer contains analog sensing, communications and impedance matching power circuitry. The MMU communicates with each Module Maximizer (either via power-line or wireless), computes the maximum operating point of each module, and provides an internet gateway to transmit performance data to the Tigo Energy analysis engine. The solution uses a combination of real-time module and string-level information to accurately compute the optimal operating state of each module. It readjusts the module by a patented process of impedance matching. The Tigo Energy solution is able to quickly and dynamically find the maximum operating state for each panel and maintain system stability during cloud cover or shading. Depending on the choice of Tigo Energy Module Maximizer, the system can be configured in either a series or parallel configuration.

Active Management

Tigo Energy gives the system owner unprecedented access to panel-level monitoring and advanced system analytics. The Tigo Energy™ MaxiManager Software allows user-configurable interfaces that enable views of power output in nearly real time, while providing a historic view of energy generation. The information can be accessed from any internet connected device. Tigo Energy’s advanced analysis engine is continuously comparing actual output to expected performance. When output of the system (or even a single PV module) suddenly or gradually falls outside of the expected range, an alert is generated. This allows the system owner or operator to manage the project so that problems can be quickly identified and PV maintenance can be scheduled based on optimal economics. For more information on the Tigo Energy MaxiManager software click Here.

More Reliability

Tigo Energy has ensured that reliability is a natural part of the solution. At the heart of this unique architecture is the very low part-count Tigo Energy™ Module Maximizer. By deploying very few, inherently reliable components near each PV module, Tigo Energy is able to match the reliability standards of today’s best solar panels. Because the Tigo Energy™ Module Maximizer is greater than 99% efficient, very little heat is generated reducing the physical impact of thermal stress. The Module Maximizer is available today in a compact plastic box that adheres to the most rigid safety and performance standards. The Tigo Energy solution will soon be available in module integrated j-box designs.

Enhanced Safety

A Tigo Energy Maximizer System includes unique safety features which detect and prevent arcing; and enable remote or on-site deactivation of the array. By designing the Tigo Energy Module Maximizers into a PV project, the system owner or emergency services personnel can eliminate voltage on the string cabling, limiting exposure to the open circuit voltage (Voc) of a single panel. Fire agencies and local municipalities have expressed a growing desire for increased safety in new photovoltaic solar installations, where high voltages can remain on the roof even after turning off the disconnect switches view news video. For more information on the Tigo Energy Maximizer Management Unit click here.

About Solar Energy PV Projects before there was Tigo Energy

Standard Panel Connection

Today’s photovoltaic (PV) systems are typically comprised of solar panels connected to one another in series strings until the voltage maximum is met (600V or 1kV as mandated by the US and Europe respectively). These strings are then combined in parallel to form an array. Because the panels are connected in series, power output of each panel will be limited by the weakest one. Therefore it is important for the panels in each string to be well matched in power rating. Environmental conditions such as shading, thermal differences, dust & debris, PV material degradation, or clouds can cause modules to perform differently within the string. The array is then connected to a central inverter, which transforms the voltage and converts DC to AC in order to put power onto the main grid.

The Inverter

Today’s inverters provide three critical functions:

  1. Isolation – through a series of capacitors and transformers, an inverter will step-up and clean the DC (or AC) power signal to meet regulatory requirements.
  2. DC to AC Conversion – direct current (DC) power generated by the solar panels needs to be converted to alternating current (AC) to be placed and transported over the commercial power grid. These conversion circuits have been optimized for 50+ years, are highly efficient and well accepted by global regulatory bodies and power companies. Often times a DC/DC transformer or boost stage will be used to bring voltages to the level required for optimal AC conversion efficiency.
  3. Maximum Power Point Tracking (MPPT) – to find the point at which the entire system can produce the maximum power at the existing solar irradiance point, the inverter applies a “trial & error” algorithm which adjusts its current draw on the system. By measuring the new relative DC power input, the inverter will determine whether to continue the adjustment in the same direction or reverse course.

Standard inverters have been optimized over decades, and manufacturers have excellent results in MPPT and conversion efficiency. However, each is limited in visibility into the system. A traditional inverter interprets the array as one large panel, making it very difficult to attain the maximum output potential from the array. In times of cloud cover and changing irradiance, it can take the algorithms in the inverter several minutes to locate a stable output maximum, causing valuable energy to be lost. The inverter may even be forced to turn off panels (activate bi-pass diodes) that are under producing current. For the economic effectiveness of solar arrays it is important to capture all of the potential energy being generated.

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Figure 2. – Voltage distribution of a typical crystalline PV string captured at Berkeley, California / Summer '08

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Figure 3. – System impact of a change in irradiance (a cloud) captured at Santa Cruz, California / Summer '08

Sample Tigo Energy Installation Sites

Below is a list of installations that you will be able to see. Please read the brief description of these to find interesting anomalies that we have detected as well as how to navigate the software.

Sacramento, California, USA

This residential installation has two identical strings of 11 200Wp multi-crystalline modules connected to separate 2kW inverters. The installation was made in early January, 2009 and grid tied on Jan 27, 2009. The upper string has been monitored in a traditional configuration since the time of installation. On July 29, the Tigo Energy Module Maximizers were added to the lower string of the system and development work was done to run experiments and make small algorithm improvements. Because this is using a standard (un-optimized) US version inverter with an isolation transformer, these Tigo Energy string results will be about 2.0% less efficient than a new installation primarily because of the extra boost stage already present in the inverter. During the weekend of Sept 4-6 (and periodically thereafter) shade experiments were made to showcase the benefits of the Maximizer. Partial shade was applied equally to the last three panels in each string. In the “summary” view, select September 5, 2009 to see that both the shaded and un-shaded modules in the bottom (Tigo Energy) string provide significantly more power output that those on the string without the Tigo equipment.

Berkeley, California, USA

The system is another large rooftop system which is perfectly co-planar (on line-leveled mounting rack) with no shade. We instrumented 17 170W modules in one string connected to a central inverter. We also placed string current, temperature and irradiance sensors elsewhere. Data is available from June 12, 2008 through October 03, 2008 when we had the first generation Maximizers on the array (monitoring only). It is also the R&D graphing UI. We randomly selected a string to instrument and it turned out to have a module which was malfunctioning (panel 13) – you can see one of the diodes is permanently active thus reducing the output of the module to 2/3 of its potential. If you look at June 17, 2008, “every second” frequency from 11am to 1pm you will be able to see the distribution of the modules in full summer sun with no clouds in the middle of the day. Toggle the view of panel 13 off by clicking on the blue square next to “Voltage_13” on the legend to the right and you will get a better view of the rest of the modules in the string. You will note an average distribution around 13% which is caused only by temperature, dust and module degradation mismatch. In this scenario we can return about 6-7% additional energy output – before fixing the malfunctioning module.

Northern Italy

This installation was made earlier this year and is a side-by-side comparison between two strings of 12 each 175Wp modules similarly positioned in an awning mounted installation. The UI is similar our production view similar to what you see with your system. One string has the full Tigo Maximizer solution (MM-EP) and is shown in the module level view on the “summary” and “energy” pages. We are monitoring the power output on an adjacent string which is shown next to the lower meter icon on the “summary” page and by viewing “power meter string” on the “energy” page. In this installation the 12 modules with the Tigo Energy Maximizer built by Manufacturer “A” while the modules in the standard string are from Manufacturer “B” (both are 175Wp rated multi-crystalline silicon modules). The historic data from this system showed the modules from “B” consistently outperforming those from “A” by 5%. You can see after installing the Tigo Energy Maximizer, the modules from Manufacturer “A” outperform the others most of the time. To view a normalized comparison of the strings from the “energy” page, select “power meter string” in the legend on the left – then hold down the shift-key and select “LMU normalized”. This will display both data sets on the graph to the right and allow for a direct comparison. Data is available for the month of March, 2009.

Santa Cruz, California, USA

This was one of the first installations made by Tigo Energy – data is available from May 27, 2008 through June 01, 2009. In this large commercial rooftop installation (3 years old), twenty-six (26) 125W modules connected to a string inverter were instrumented. The data is presented differently than on today’s commercial systems – it is a graphing application which can give a per-second view (voltage, current, temperature, irradiance) of all the modules that are being monitoring. This version of the Maximizer is ONLY MONITORING – there is no fixing of the module output. The default view is voltage output readings of each panel. Any value may be viewed or eliminated by clicking on the colored box next to the parameter in the legend to the left of the graph. The interesting aspect is to see the performance of a system at the module level in a well architected (no shade) typical commercial application. This is a very effective tool to demonstrate that module mismatch does occur even in “perfect” systems due to environmental issues other than shade. It also serves as a foundation for us to more accurately predict the magnitude of impact of each issue – we were able to add shade, clean panels, etc. to isolate the impact. We are also able to look at the effects of clouds – for example, if you select June 14, 2008, “every second” frequency from 11am to 1pm you will be able to see the array instability when small cumulous clouds pass over the modules (ex. starting at 11:27am). In these installations the amount of projected energy gain we can return with the latest version of our Maximizer is roughly half of the average distribution percentage (of voltage) from the best to worst modules in the string. When you see a distribution of 12%, we can return 5-6% additional energy output during that time period. The distribution percentage at any given point in time can be read from the mouse-over cursor when placed on the graph.

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