Enatel’s SYNERGi solution achieves 90% less genset runtime

Enatel Energy offers an expansive portfolio of fully customizable DC power systems and industrial battery chargers, designed to meet every power conversion requirement. Solutions offer flexibility and scalability by way of rack-mount, hot-pluggable combinations of modular AC-DC rectifiers, DC-AC inverters and DC-DC converters with advanced monitoring and control.

In this interview, Murray Wyma, CTO DC Systems, Enatel Energy, talks about the work that the business has done recently in Mexico, explains why MNOs are likely to see energy costs go down in the future, and gives an insight into what makes Enatel Energy’s products so unique.

TowerXchange: Please give us a brief overview of your company for our readers that aren’t familiar with you.

Enatel Energy is a division of Enatel which was founded 17 years ago by the same personnel that created Swichtec Power Systems, a company successful in designing and manufacturing switch-mode power solutions primarily for the telecommunications industry. Based on over 30 years of experience, our core business is the design and manufacture of power conversion products for the telecommunications, IT, utility, materials handling and renewable energies sectors. Headquartered in Christchurch, more than 90% of everything we design and manufacture is exported internationally to over 70 countries throughout the world. Enatel is a part of IDEAL INDUSTRIES INC. a global, diversified family business designing and manufacturing products for the electrical, wire processing, data communications, aerospace, automotive and construction industries.

Competing with the best in the world, our products include a range of high-efficiency rectifier and converter modules, hybrid power systems, along with rack and compact power solutions, supported by embedded and GUI-based software, as well as a range of ancillary products. We also participate in the renewable energies sector with a range of high-efficiency solar inverters and modular, high-efficiency battery chargers for the material handling equipment industry.

At Enatel, our core focus of research and development is utilizing cutting-edge technology creatively so we can offer our customers better products, performance efficiency and value for money. This approach ensures that we stay committed to the continual development and enhancement of our suite of AC and DC power systems, intelligent modular rectifiers, DC-DC converters, control and monitoring options as well as motive power and solar energy solutions.

TowerXchange: Could you share some details of one of your more challenging projects since we last spoke?

Previously we discussed the Sinuoso site in the Sonora desert in Mexico.  There we reduced generator run time by 90% and reduced CO2 emissions by more than 56,000kg per year.

More recently we have been very active in Australia with its challenging remote (and critical) sites.  These sites have a high dependency on solar (20 to 30kW is not uncommon), and many have dual generators.  Uniquely, to avoid the use of ATSs, the dual genset sites run two banks of rectifiers, with the outputs combined at the 48VDC level.  This presents numerous advantages, not only eliminating the ATS, it provides N+N redundancy while allowing the ability, if necessary, to run both gensets at the same time for faster recharge.

These systems are complex.  Enatel’s advantage is that all of the control of the gensets, battery charge-discharge & load management are centralised in a single controller.  This simplifies the complex solution.

The main challenges for us now are not so much the functionality of our gear, but education of users, and remote connectivity & visibility.

We are constantly amazed in this day and age at the number of telco’s & operators who do not have remote serial communications.

A specific example of how important remote comms are occurred recently.  A site in remote Australia (2 hours drive from the nearest settlement) reported an “urgent” alarm (there were only two dry-contact alarms connected to the NOC, urgent and non-urgent).  A technician was sent to site and found he could not start the generator from Enatel’s controller.  The assumption was the controller was at fault.  A more knowledgeable services technician was sent to site.  Upon arrival he found the genset had simply run out of diesel (by the way, the solar power using Enatel’s solar converters continued to supply site power).  He then had to make a return trip, which was now the 3rd visit, to replenish the diesel (limited supply).  Still the Enatel controller would not start the generator.  “Phone help” was requested from an expert operator.  Fortunately, we have a switch that simply opens the generator start contact at the output of our controller. The genset still did not start, thus indicating the problem was at the genset.  Upon investigation, the genset lockout did not release itself after the diesel was replenished which required the technician’s intervention.  Once this was fixed, everything worked perfectly.

Although heavy on detail this example highlights the importance of both training and remote communications.  A correctly trained technician using Enatel’s remote dashboard (a simple http connection is all that’s required) could have diagnosed the issue prior to travel to site.  Only one site visit would have been necessary instead of three.  The savings in time and money are obvious.

TowerXchange: What is your installed base at cell sites worldwide, and what is the approximate energy mix within that installed base?

Since we last talked, we have set up local representation on the African continent and seen some major deployments of off-grid systems – especially in Kenya.  Globally, we are now running into the thousands of off-grid systems.

Although system volumes in Australia are not huge, the installations are high power, and the environment harsh.  Some sites can take a day to get to (not disimilar to many African regions) so there is a heavy reliance on solar, large batteries (some over 7,000Ahrs) and often two generators.

All off-grid sites we have supplied in Australia have a significant solar component.  Many of these sites run almost 30kW of solar, making the generators mostly for emergency use.  However, about 20% of these sites also run dual generators, a number with dual 36kVA gensets.  Some sites are also “sweating the assets”, installed with a new 36kVA generator along-side the old 10kW generator.

All conceivable climates and conditions are encountered in such diverse geographic locations, everything from integrated generator solutions and outdoor cabinets to walk-in shelters and buildings. We see energy mixes from the normal single cell/single tenant sites with average loads of approximately 1kW through to large sites and multi-tenant sites of 4 or 5kW.

We are even seeing requirements for off-grid solutions approaching 9kW load. In sites this size, the use of cyclic batteries becomes uneconomic, often forcing the owner to once again consider 24/7 operation of the generators unless large renewable energy sources are available. This could be a controversial statement, but as long as a genset is operating at maximum efficiency, then no amount of cyclic charge/discharge delivers comparable fuel use in terms of overall litres per kWhr of energy.

TowerXchange: Should cell site energy solutions be owned and operated by MNOs, towercos or ESCOs?

As an embedded power system provider, we are agnostic with respect to the energy solution’s owner. As time progresses, we are obviously seeing more of a shift from MNOs towards towercos and ESCOs. This enables more efficient use of tower space and energy as now many sites are multi-tenanted. Ultimately this should lead to lower costs for the MNOs and consumers. However, for MNOs who already own the tower infrastructure, retaining ownership of the tower can ensure fixed levels of tower (and power) servicing cost rather than be exposed to the risk of rent increases. We are also focussed on next generation power architectures for initiatives that migrate a towerco into a powerco, allowing monetisation of those traditionally distributed stranded assets. This applies similarly for an MNO looking to diversify – as some are.

The other factor in the equation is the ease of deployment and monitoring of the power solution. This is where Enatel Energy differentiates itself by offering scalable solutions that monitor and report full energy logging of all system parameters (loads, battery, charge/discharge, genset kWhrs, solar kWhrs, and so forth - hourly, daily, and monthly).

As mentioned, we are seeing a big increase in solar power supplementation for remote sites and our easily integrated converters offer smart functionality such as solar optimisation (minimising genset run-time).

For Enatel, it is all about making life easier for the energy solution owner, and of course, providing secure power with high 9s uptime to meet the most demanding SLAs.

TowerXchange: SLAs often demand 99.5% or higher uptime – tell us about the reliability and autonomy of your solution.

Our designers come from a long history of DC power in the telco space (since the mid-1980s). The telco up-times typically required are greater than 99.9999%. The best way to describe how we provide high 9s reliability is through the quality of design in our products, redundancy and plurality of supply. The other factor is fail-safe operation. No matter the state of any controller/monitor, the core power system operates autonomously. This is a cornerstone of telco DC power system design.

We include patented features such as dynamic generator anti-stall in our products to ensure higher uptime. As a result we can raise alarms if the generator goes into a ‘low power’ state, possibly due to poor fuel quality, blocked air filter, et cetera.

The other benefit of detecting the generator’s peak power capability is that we can then programme the genset to operate at its peak efficiency during the battery recharge.

Enatel Energy offers optimal dynamic phase-balancing where we can adjust rectifier output to ensure the phases on the generator are balanced (within the scope of the applied load/battery recharge).

Another feature we see widely deployed with our gear is to use our 48V/12V DC/DC converters to keep the generator battery float charged.  This is particularly important in large solar sites where the generator operates only intermittently.

The intention of the SYNERGi hybrid solution is to ensure that the generator will run efficiently. A further line of defence to prevent the site collapsing is the ability to control load shedding. SYNERGi has the ability for the operator to shed their loads and maintain critical site and transmission capability. These features are unique to Enatel Energy and demonstrate Opex savings through optimised functional capabilities which maximise uptime and avoid unnecessary truck rolls.

TowerXchange: How is your solution scalable to accommodate the increasing power requirements as multiple tenants are added to a site?

Allowing space for extra power modules and battery connections can be easily catered for at the time of design for minimal cost. When a site is first deployed, the system frame can be supplied with a minimal number of power modules. This can be done through modular configurations that support the use of wind turbines and expansion shelves.

We are also currently addressing multi-tenant metering of up to six or more tenants.

Of course, we cannot talk about cyclic power systems these days without bringing up the topic of lithium batteries.  This is a whole subject in its own right, but the advent of lithium batteries now gives us the ability make the battery more scalable than with lead-acid batteries.  Space for batteries can be allowed for from the get-go, and batteries added as either load or autonomy demands.

As a side-note, when loads are high and autonomies are long, batteries sizes in the thousands of amp-hours can be required.  In these applications lead-acid batteries still remain the only viable solution – or combinations of lead-acid and lithium.

TowerXchange: Should M2M technology be built into energy systems, or should third party remote monitoring be used to provide visibility into performance?

Certain levels of M2M technology are already built into Enatel Energy systems. We have built in full SNMP functionality through to SNMP V3. This includes a full suite of traps, gets and sets. This enables easy integration of third party SNMP managers. This is advantageous due to their well-proven legacy and in many cases SNMP managers are already in use by our clients and end-users. Further to this, we have built in UDP communications for use with our craft tool which enables set-up, log access and bootloading facilities across a narrow bandwidth (sometimes 2G) sites. Designing ‘narrow band capable’ remote communications is essential for the developing nations market.

As mentioned earlier, it is vitally important to be able to maintain the communications channel to the device from the equipment manufacturer remote control facility. Monitoring solutions, where third party site control systems have been added to our monitoring, limit access to our equipment, blocking visibility and the ability to change key system parameters.

TowerXchange: Please sum up how you would differentiate your solution from your competitors’?

Enatel Energy presents the most complete, comprehensive telco hybrid system on the market with the SYNERGi system. With SYNERGi, users can automatically generate maximum generator power tracking and anti-stall. They can automatically set their generator loads to a predefined optimum level and carry out dynamic phase balancing. Our solution also allows users to control two generators simultaneously and alternate their cycles to synchronise their services.

Users can also seamlessly include green energy sources through solar and wind converters and take advantage of true plug-and-play power modules (rectifiers, solar and wind converters) with self-setting addresses. The system also provides full kWhr logging of all energy sources (grid, gensets, solar and wind) on an hourly, daily and monthly basis. Just as importantly, the solution can be accessed remotely via HTTP, SNMP (v2C and V3) and UDP scripting.

SYNERGi features a one-step front-panel control that provides a battery initialisation (commissioning) charge to enable installation technicians to set the system and walk away without the need to return to site. Generator start-up has adjustable settings that can be based on time of day (up to two periods per day), battery voltage, battery Ahrs (battery capacity) and periodic genset tests (independent of other settings). The start and stop functions can be enabled simultaneously to provide maximum security.

If a battery is stolen, disconnected, lost, or found to be ineffective, the system will detect the problem and notify the user. Battery history can also be logged to enable battery warranty claims if necessary. As previously mentioned, the system can be optimised for solar use to ensure that the generator does not run unnecessarily by predicting the ‘solar day’ and limiting the use of the system to ensure maximum possible solar harvest.