Why solar continues to strive ahead as the best solution for remote telecom sites

With over 1,000 systems deployed globally, Apollo Solar’s systems are used my many major players in the telecom market. In this interview, TowerXchange speaks to the company’s CEO John Pfeifer to understand how solar’s cost, reliability and suitability for the telecom market stacks up to other forms of power generation.

TowerXchange: Please can you introduce Apollo Solar to TowerXchange readers. How extensively have Apollo systems been deployed? Who are some of your key customers?

Apollo Solar is a manufacturer of the electronic equipment required for supplying electricity to remote telecom towers. We design and build all the hardware and develop the software in our plant in the USA. Our strong suits are reliability and low cost of maintenance. Over 1000 Apollo systems are installed with sites on every continent, and the majority in the challenging environments in Africa. 

Our equipment is completely wired and tested and shipped in the simple cabinet shown in figure one. This is just 1000mm wide and 1200mm tall and it IP66 sealed against water and dust.

We sell directly to ESCOs and installation contractors as well as tower companies and telecom operators. Our customer list includes Orange and their partners, American Tower, Camusat, Tower Company of Madagascar, Solene and others.

TowerXchange: Space constraints are typically cited as one of the biggest barriers to the use of solar on telecom sites. Typically what kind of footprint is required for different power loads with Apollo’s system? What is the sweet spot when it comes to the use of solar power at towers and what size is the addressable market for the use of solar in telecoms?

The typical tower requires about 750 watts per BTS, so an average site with 2 BTSs needs about 1.5 kW continuously, plus another 500 watts for a microwave backhaul channel. If we focus on the pure solar systems with no diesel generator at all, 12 kW to 15kW of solar array will do the job. Today the average PV module will produce 160 watts per sq metre, so 12kW requires 75m2 and the 15kW array will need 94m2. When the space is a constraint, we simply leave the diesel generator on the site and let it run for a few hours each day. Such a hybrid system can be sized anywhere from 0% to 99% solar, so there are no longer any sites which are too small or too large for solar. Apollo Solar makes pure solar systems for loads from 250 watts to over 5kW of DC Power and Solar/DG systems with 2kW to 15kW of load.

The most popular system is 2.5kW, but that is increasing as more equipment is installed on the towers. Pure solar systems are most cost effective at the small end, but hold their own up to 3kW to 4kW of load depending primarily on the real cost of diesel fuel delivered to the sites. Our hybrid solar/DG systems do not have any limitation on size, they just run the generator for a little longer each day. Since the amount of power is not a limitation, our addressable market is equal to the number of towers that are currently running on just the diesel generators. The last numbers we saw published totalled about 800,000 remote tower sites that were running on diesel generators world-wide.

TowerXchange: With many maintenance contractors more familiar with mechanical gensets rather than solar systems, how has Apollo Solar developed a system which tower owners can be confident will be properly installed and maintained?

We have trained many maintenance contractors on the installation and support of our systems. We have been successful at doing this in the Americas, Australia, Asia and Africa. The secret to the reliability of our systems is that they require almost nothing in the way of maintenance or support; solar has no moving parts, there is nothing to wear out and nothing needs to be adjusted, oiled, replaced or rebuilt. Apollo builds our electronics with redundancy for every critical component so the chance of a system going down is extremely small. In the case of a failure the power electronic parts can be swapped out by anyone. Furthermore, our integrated remote monitoring software allows us to watch every site along with the tower owner, and the maintenance contractors, from anywhere on the planet. 

In the end, confidence is built over time and we have done that since our systems that were installed in 2008 are still working today, 10 years later. Not all solar electronic manufacturers have achieved this level of reliability because they cut corners with critical parts.

TowerXchange: The cost of solar panels themselves has come down dramatically in recent years but looking at Apollo’s solar hybrid system as a whole, what developments have there been to improve the TCO?

Certainly our pure solar systems are easier to purchase today when the cost of the solar panels is at $0.28 per watt as compared against about $4.00 per watt ten years ago. Over that same period, Apollo Solar has reduced the costs of our electronic cabinets by standardising on components to take advantage of economies of scale while increasing our volume purchases. Today, the total cost of ownership of a pure solar or even solar hybrid systems is largely driven by the cost of the battery. By partnering with battery manufacturers our customers have been able to negotiate lower prices with long term, higher volume contracts.

TowerXchange: Can you tell us a bit more about the components that go into Apollo’s solar hybrid systems; which partners do you work with and are these changed? What is manufactured by Apollo? How do the components compare to others in the market?

We deliver a cabinet with all the electronics inside so that the installation is a simple matter of attaching the solar array, the battery and the BTS. Apollo manufactures everything inside the cabinet for the pure solar systems. We integrate a rectifier into the cabinet for the hybrid systems which is made for us by a high quality rectifier manufacturer that brings that expertise to our partnership.

The major difference between Apollo’s equipment and others’ is that Apollo designs and builds everything with our own people. This gives us several advantages: We know how to support and enhance the products going forward, we can control our costs and delivery times, and we are not exposed to trade tariffs from China. Some others in this market have simply installed components built by others into a box of one size or another. 

TowerXchange: How do you see the shift towards renewables changing in the telecoms space and what are the factors driving this? Do you see a role for other renewables beyond solar?

It should be clear to everyone that solar energy is the best solution for towers that are not connected to a reliabile electric grid. Besides cutting the Carbon Dioxide emissions to zero, solar is a simple, low cost and complete answer to the problem of fuel theft. Apollo Solar has proven that solar powered sites experience essentially 100% up time, thus eliminating the costly down-time penalties. The headaches of generator maintenance are minimised when the run time is cut with the hybrid systems or zeroed out with pure solar. As the tower companies, ESCOs and others begin to focus on cutting their energy related operating expenses, solar is growing in popularity and will continue to do so.

We work with other renewables. Apollo can connect to any electrical input and prioritise the use based on the cost. There is nothing wrong with wind power, and we have installed sites with wind turbines feeding the batteries. However, small turbines of the size required in this market are not as cost effective as the megawatt turbines that make the news. And, unfortunately the small turbines have not been reliable. Wind is free energy, but it is much less predictable than solar, so we must have enough solar to power the tower without any wind power. Any extra energy from the wind turbine is not of any use to us unless the wind just happens to coincide with 3 days of dark weather. Furthermore, we see no reason to add moving parts that require maintenance after we just got free of those problems by eliminating the diesel generators.