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 14 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.

Competing with the best in the world, our products include a range of high-efficiency rectifier and converter modules, hybrid power systems, and rack and compact power solutions, supported by embedded and GUI-based software, along with 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 creative, cutting-edge technology so we can offer our customer’s 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?

The Sinuoso site, located in North-West Mexico, on the edge of the Sonora desert, is challenged by its environment and is a fully off-grid site with 2G (including air-conditioning) and 3G cellular loads in self-contained cabinets.

A hybrid system had previously been deployed with a mix of DC rectifiers, solar converters and AC inverters, from a range of suppliers, with a third party PLC controller for supposed hybrid functionality. This was a good example of an attempt to pull together a hybrid system, including solar from a disparate array of different manufacturers’ equipment that never worked as intended. The decision was made to upgrade the site with our SYNERGi solution with five 2kW solar converters, nine 2kW rectifiers (phase-balanced) and six 1.2kW inverters, to provide the necessary efficiencies and cost savings.

The SYNERGi hybrid power system cycles the batteries, saving diesel and maintenance expenses by operating the existing generator in its optimum efficiency power range for longer periods. The ‘solar optimization’ feature also ensures that the genset does not run if solar power is available. SYNERGi incorporates its own self-learning algorithm to track sunrise through the seasons, to give well-defined stop conditions to the generator to ensure it does not run unnecessarily during the ‘solar day’. It does not require connection to external date or time references, and does not require links to weather forecasting web pages. It operates autonomously.

The SYNERGi solution is modular, requiring about a quarter of the space, and represented a harmonized, single-controller solution where all the power modules work in a unified, coordinated manner to optimize Opex.

The battery is usually the crucial element in a hybrid system, but in this instance a reconditioned set of 1500Ahr AGM batteries was supplied to analyse cyclic performance over time before deciding on the best battery fit – a lithium battery solution is currently being considered.

Over the month of August 2016, SYNERGi delivered some remarkable results. In fact, we’ve reduced the genset runtime hours by 90%, the usage of diesel and the CO2 emissions by 87% and the maintenance costs by 83%. This means annual CO2 savings of 56,052kg and monthly savings in excess of US$3,400.

ROIs and paybacks are site dependant, but in most cases full payback on these sites can easily be achieved in less than twelve to eighteen months.

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

Enatel Energy systems have been installed within hundreds and thousands of cell sites globally, with numerous hybrid systems deployed through a network of integrators. These systems are located in Kenya, Madagascar, Chile, Tanzania, Colombia, South Africa, Myanmar, Nigeria, Mexico, Haiti, Australia, Pacific Islands and New Zealand.

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 (as in the Sinuoso example) and multi-tenant sites of 4 or 5kW.

Lately, we are 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 would deliver 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 solutions 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 must 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 et cetera., hourly, daily, and monthly).

We are seeing a big increase in solar power supplementation for remote sites and our easily integrated converters offer clever functionality such as solar optimisation (minimising genset run-time) as mentioned in the Sinuoso example.

For us, 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).

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.

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 to the developing nations market.

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, limited 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 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 through 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.

Enatel Energy will be exhibiting at the 5th Annual TowerXchange Meetup Africa & Middle East, being held on 3-4 October at the Sandton Convention Centre, Johannesburg. Visit the website for more information