Percent two years ago, up to 17% in the past year. This is despite the downturn that the market had experienced in 2024 following several very strong years of growth. This year has been a rebound year. We rebounded very strongly and have been financially performing quite well this year. In addition to our MLPE product line, we have expanded our product portfolio with new products including what's called a hybrid inverter and a residential battery storage solution. It's geared primarily currently for the U.S. and the German market. We expect to continue refreshing that product line and expanding upon that product line in the future as well. A few years ago, we bought a software company in Israel and built our Predict+ software product line in that area.
This software is sold to utilities so that they can match supply and demand, demand being from metered customers, supply being the supply of wind turbine, gas, and fossil fuels. That is, can AI algorithmically use the weather to predict the supply and demand software so that you can arbitrage power if you have too much or be able to provide more power as demand increases. We're currently an outsourced contract manufacturer-focused company. We manufacture in both Thailand and in China. Thailand is for the U.S. market. China would be for other markets outside the U.S. As you're fully aware of the tariff situation there. About a month ago, we announced a partnership with a company called EG4 to offer an optimized inverter solution in the U.S. market next year. We will be manufacturing in the U.S. next year for the U.S. market.
It has a number of advantages to it, including offering buyers of it access to the ITC and bonus tax credits and the 45X manufacturing credit for ourselves. We sell primarily through distribution. Many of these distributors are not household names, but most of our sales go through the distribution channel, and the installers will buy our product for installation at the home or business. Only in maybe generally only in the bigger EPCs we would do direct business with for utility-scale projects and such. For last year, we did $54 million, which is a big decline from the $146 million in the prior year, but through the first six months of the year, we've done $42 million. You can see that the revenues were down in the prior year 63%, but up 91%.
The current year resembles a lot more closely the previous two years, which we had 80% + growth. Cash was, as of this all, $28 million, about $18 million of inventory, $50 million of a note convertible. Our sales are spread, as I mentioned, 69% in the EMEA region, 22% in the Americas, which includes Canada and Mexico, and 9% in APAC. Brief history about Tigo Energy and its evolution. We were founded in 2007. There was a long gap here between 2015 and 2007. We spent a lot of years researching and developing what has now become optimization technology. Us, along with SolarEdge, developed optimization technology around the same time period, and it's used to be able to improve the performance of a string of panels that are hooked up along an electrical line.
There is a lot of R&D effort that went into the creation of our product in this little box that sells at a very economical price, and we provide a 25-year warranty on it. It's quite important that you get it right. We had a partnership. One of our competitors chose to combine their inverter with their optimizer solution to offer an optimized inverter solution. We opted for a slightly different path. In the 2016 to 2019 timeframe, we partnered with a European company to offer something similar. It worked for about three years. We dissolved the partnership, really branched out on our own around the time of COVID, began to introduce some new products, really experienced some explosive growth, especially in 2022 and 2023, 80% a year in each of those years, culminating in our DeSpac IPO of May of 2023.
Subsequent to that, the market declined kind of in unison for much of the industry. I'll just briefly tell you the reasons behind that. If you recall, in COVID, there was a lack of production going on, and we had, at the same time, a spike in demand. You had some external influences like the Russian invasion of Ukraine forcing people to, wanting people to get off of Russian gas, more into renewables. You had IRA subsidies and repower subsidies in Europe. You had a big stimulus in the demand equation, but you still had those really tight supplies with COVID. In that period of time, 2022 and 2023, customers were on allocation. We ourselves were on allocation. Let's say you wanted to get 10 pieces of something, they told you you could only get five. As with human nature, what do you do?
You say, "I want 20," so that you can get 10. That works for a while, but then eventually when things sort of normalize out, you get the 20 and you only need a 10. I would say the last half of 2023 and 2024 were a period of destocking where people simply had too much inventory in the channel and weren't ordering much. The industry went into a downturn, and it's mostly fully resolved itself. For us, it took about nine months. Others a little bit longer. Now as we look back on it, the inventory in the industry, as I would describe, is much more normalized with ship into the distributor channel, roughly equal to what the end demand is. Along the way, we continue to innovate.
We obviously had to cut your costs so that you can manage your cost structure, but we didn't want to stifle the growth and jeopardize our pipeline. We continue to introduce new versions of our TS4-A series optimizer solution, and we continue to innovate the same way today. A little more about just the industry in general. There is the overall global solar panel industry growing at single digits, very, very large globally. Within that is optimizers, DC optimizers that are also growing at a faster rate, becoming more and more prevalent within just on the solar panel itself. At the beginning of the decade, that growth for us was about 14%.
If you look at McKinsey data, it grew at that rate, and then you saw that big steep drop-off here in 2024, about 44%, and then a solid bounce back here in 2025, 62%, where the rest of the decade calls for about 18% growth. There was an expectation that DC optimizers will continue to take up more space in the overall panel market as a component that's used within it. Down at the bottom is the growth, expected growth of 7% for the residential storage market. Along the way, we've continued to gain share. A lot of it has to do with our technology, our positioning, our reliability. I'm happy to tell you more about that. Helping our growth has been our ability to get market share in this large industry, growing from 9% to 17%.
Underpinning all of this is just the fact that solar has become, on an unsubsidized basis, the lowest form cost of energy, very fastest to deploy. A lot of this is you're seeing the AI data center trend. You're seeing the need for energy. This is all just underpinning a continued long-term trend towards more energy usage, more need for energy, and solar is a big component of that. We don't make the solar module on the left, and we don't obviously make the grid on the right, but these are the three areas that we offer solutions in. The MLPE optimizer device is about 85% of our last year's revenues. More recently, we've introduced a hybrid inverter and a battery for the residential market, comprising about 10% of revenues. Through our acquisition of a company a few years ago, we have our Predict+ software platform for utility customers.
Along with licensing revenue that we generate, this makes up the last 5% of our company. Here's an example of optimization at work, MLPE work. This device that I have in my hand just simply clips underneath the solar panel. We have more than 10 million of these units in the field today, offer a 25-year warranty on it, very low failure rates, and they're certified to work with more than a thousand other inverter types. We work with a number of inverter manufacturers so that they can offer optimized solutions to their customer. There are three features to choose from that I'll tell you about here. The first is optimization itself. When you're stringing a line, an electrical line, you need to have a constant current. If you have a panel that might be shaded or positioned in a different orientation, you're going to have a different power output.
To equalize that, there's something called maximum power point tracking, which works with voltage and current in order to get the maximum amount of watts out on a line. Our device does that. You can get a 6% - 8% improvement most of the time in the panel performance by having optimization. As I mentioned, one of the main competitors in our industry went to market 10, 15 years ago with an optimized inverter solution, and it has been very successful. The need for optimization has been proven in multiple white papers, and the benefits have been clearly demonstrated. The other benefit that customers will like is the ability to monitor at a panel level how their system is performing.
As opposed to a system level where you might see how the overall system is, the granularity of module level monitoring allows you to actually see which monitor is performing well, which is not. If you can imagine yourself as an operator of a lot of panel systems, you would want to know if one of those panels is not working properly, and that would enable you to be able to take corrective action and fix it as opposed to having to physically go out and check things. Finally, there's the safety feature here. Safety has become more and more of a regulation around the world. Rapid shutdown is not everywhere in the world, but it's becoming more and more commonplace. Just like the name sounds, it lets you rapidly shut down the solar panel system.
If you, for an emergency or if you need to do a check or for some reason you need to go up on the roof, you got to be able to do it safely because without it, the sun is still hitting photovoltaics and the PV systems are still generating electricity. Unless you have something to stop that, it can be dangerous. On the right here, on the top, you can see where shaded conditions would help necessitate the need for optimization. If you've got shaded panels, it's going to disrupt the whole panels of the whole system. Optimization makes adjustments, so you can get performance out of the whole system. In the middle part, it's just a lot of panels that need monitoring, and on the bottom, you have a system that's sitting on water. Rapid shutdown is very important. Water and electricity don't really like each other.
Over the past couple of years, we've introduced a hybrid inverter. What hybrid means is that you can use one inverter to convert power from both your grid, solar panel system, or your battery system. The alternative is that you could have one inverter for your battery and one inverter for your grid-tied system in PV. You eliminate the cost of having to get two different inverters. That is more and more becoming a continuing trend as battery development occurs and adoption rates increase. We also offer a battery solution to go with that, along with the transfer switch, which can transfer as needed. Here's a little pictorial of our intelligence platform with more of the minutia of each of the panels and all the statistics that underlie that. Our customers that use our monitoring really enjoy seeing this level of granular data.
You can't get this unless you have module level monitoring. You won't be able to get it just at an inverter level. Our Predict+ software, here are some of the customers. They're primarily the company we purchased is Israeli based, and they have a dominant share in the Israeli utility market. These are some of the customers. More recently, we've been expanding our efforts to offer the software in Europe and the Americas, and we see that as a source of growth as we move forward. Just some of the advantages. If you're an installer, why do you want to buy Tigo? Selective optimization. These are unique to Tigo. Selective optimization means that we've architected our device to only optimize when it needs to. There's a lot of advantages to that. You don't have a high duty cycle if you don't need to always be on.
You have a low failure rate because you have that low duty cycle, and you're more energy efficient because, again, optimization does use energy. Selective deployment is another nice feature in that you don't have to use it on every panel, so you can selectively deploy it on the panels that need it. We also are the only company that can work with almost any inverter type out there. We are committed to an open architecture system for the industry and are used by many inverter companies to optimize their systems. Very high reliability, low failure rate. It's very important. Once you install, the installer does not want to come back and have to go replace equipment. That's why we have the 25-year warranty with a very low failure rate, high reliability.
Our GO ESS, our battery system, is DC coupled, and all that really means is that sunlight comes in as DC and can go into the battery as DC. The less you have to convert the energy between DC and AC, the more energy you're saving. You can lose 5% - 6% every time you do a conversion. Our software platform, it commissions very quickly. You can see literally these clips will just clip onto the back of the solar panel and just start optimizing from the get-go. It's all backed by patented technology and know-how. Our financial overview in 2022, you can see we grew more than 80%. Similar achievement in 2023. We had a high watermark of about $145 million that year. Had issues in the macro picture in 2024, went down to $54 million. Since then, have recovered quite nicely.
Guidance that we gave in our last call is anywhere between 85% and 94% growth for the whole year. Along the way, we've also been able to improve our cash generation. We became cash positive a few quarters ago. We came EBITDA positive last quarter, and our guidance is $29 million - $31 million in the current quarter, up substantially from Q4 last year, which was about $17 million and change. At the high end, we're guiding net operating profitability. The top line has been accelerating for us. The rebound has been quite solid, and the profitability has, we've been able to leverage our P&L to generate cash to the bottom line on that. We've adjusted our OpEx as we needed when we had the downturn.
That has helped us to increase our EBITDA margins, which, when we were at our high watermark before the downturn, was about $68.7 million and 19.6% EBITDA margin. Our target model is 40% on the gross margin and 20% - 25% on the EBITDA margins. Diverse array of customers, my last slide here. We don't have any, we have one 12% customer. As I mentioned, most of our customers are distributors, large distributors around the world. We do have a heavy focus in the EMEA region. If you think about it, there's a lot of countries that make up the EU, and the installation of solar is 5x what it is in the U.S. It's a big market in itself. That concludes my prepared remarks, and I'm happy to take any questions if you have any. Yes.
Can you help us understand the logic behind the residential battery inverter business? It just seems like a crowded space from what I know. I'm not quite sure what you bring to the table. It's pretty entrenched in large corporations.
It is, but if you think about it, a lot of the cost is in the customer acquisition. We've acquired our customers with our award-winning MLPE solution here, and the inverter and the battery can be complementary to that. If you look at the revenue of our competitors and took away what they sold in batteries alone, they'd be half the size. It is quite crowded, but we already have a really good go-to-market strategy with our product that we sell today. It's a $30 device, and you can imagine if you're selling an $8,000 device to go with a $30 device, obviously your ticket size increases a lot more. It's a cross-sale, but it's part of a solution. A lot of customers want full solutions, so it is a natural direction to try to offer a complete solution.
That's why we're going after the new products, inverter, battery, and the software. It all ties together.
Have you spoken to the attach rate, if you will, of the batteries and inverters versus your MLPEs and just how that strategy's worked to date?
Yeah, the attach rate is increasing in general. It is very high in the European market. It hasn't been that high in the U.S. market, not from our experience. The U.S. market has been changing in our favor recently. Some of that has to do with just the way the market entrance and the dynamics have played out. You've seen a couple of bankruptcies. You've seen SunPower and you've seen Sonova. They had some significant vendor tie-ups that excluded smaller competitors like us. With the fragmentation there and the bankruptcies, we're now getting that business. It's becoming a little bit more of a fair playing field in the U.S., and we're able to grab some additional business that way. We're very excited about what's happened there. We're also excited about our partnership for next year, our EG4 partnership to offer an optimized inverter solution.
Again, it's a solution that you're offering, not just a component. It's going after a well-established market against an established competitor that will be the second company to be able to provide that kind of solution. Giving that ITC credit to buyers is what they really want in the U.S. market. There are strategic reasons why we're doing what we're doing.
Can you just talk to, it seems like at least the residential market is headed towards more of a closed system as opposed to one that's open. Correct me if I'm wrong. Also, just talk about the commercial market or the utility-scale market. Is that more of a utility-scale market as opposed to a closed system?
I'm not seeing it being as much of a closed market as you would say for Resi. The utility market is a big whale market, and it's a long lead time. RFPs take six, nine months to get from initial stage to closure. The last big deal that we announced was a project in Madrid, 142 megawatt system. There's a number of those still in the pipeline, but it's a much longer sales cycle than the typical Resi or commercial. I mean, we're doing well in both Resi and commercial right now, both in the U.S. and abroad.
That's all the time we have. Thank you everyone for a great first day. We'll see you tomorrow.