Moving over to the full-year 2023 results. Our full-year 2023 revenue was $25.1 million, which is flat when you compare it to the 2022 results. The fiscal 2023 net loss was $4.6 million or $0.19 a share, which compares to a net loss of $2.4 million or $0.14 a share in the fiscal year 2022. The increase in the net loss is due to the lower gross margin and the increased provision for bad debt. Our overall gross margin in fiscal 2023 was 40.6%, a decrease of 3.7% from the fiscal year 2022 gross margin which stood at 44.3%. The current year gross margin was negatively impacted by the increased material and labor costs incurred to address engine replacements and for the obsolete inventory provision that was recorded. Excluding the obsolete inventory charge, our 2023 overall gross margin would have been 42.2%.
Operating expenses increased $1.2 million or 8.9% to $14.6 million in fiscal year 2023 from $13.4 million in 2022. This is due primarily to a $974,000 increase in the bad debt provision, which is resulting from a combination of the increased $744,000 bad debt provision that we recorded in the current year on the installed receivables. And you may recall that in 2022, we had a $300,000 bad debt recovery, which reduced our bad debt expense for that period. Further, in 2023, we saw increased administration costs due to the maintenance contract acquisition, which impacted insurance and vehicle expenses. Moving on to the EBITDA and adjusted EBITDA. For the fourth quarter, the EBITDA loss was $1.7 million, and the adjusted EBITDA loss was $527,000, which compares to an EBITDA loss of $1.3 million and an adjusted EBITDA loss of $1.1 million in the fourth quarter of 2022.
As previously discussed, the Q4 2023 results were negatively impacted by the installation bad debt and obsolete inventory provisions that we reported in this period. For the full-year EBITDA, our EBITDA loss was $4 million, and adjusted EBITDA loss was $2.6 million which compares to an EBITDA loss of $2 million and an adjusted EBITDA loss of $1.7 million in FY 2022. The higher loss in the current year was driven by lower gross profit margins due to the engine replacements and the onetime charges that we’ve recorded against earnings. Depreciation and amortization expense increased in 2023 due to the addition of several vehicles and the amortization of the customer contract intangible assets recognized as a part of the Aegis acquisition. Our fiscal 2023 depreciation and amortization expense increased $139,000 from the 2022 levels.
Moving to the segment performance for the fourth quarter. Our products revenue increased 77% quarter-over-quarter, and we saw increases in both our cogeneration and chiller products. Our products gross margin decreased to 19.4% from 32.1% in the fourth quarter, and this is due to the obsolete inventory provision that we recorded. Excluding the provision, our products’ gross margin would have been 37.5%. Services revenue increased 19% quarter-over-quarter due to the acquired maintenance contracts. Services gross profit decreased to 51.3% in the fourth quarter from 60.1% in the fourth quarter of 2022, and this is due primarily to the obsolete inventory provision and the higher material labor cost. Excluding the inventory provision, our services gross margin in the fourth quarter of 2023 would have been 53.6%, which is more in line with our expectations.
Moving to the segment performance for the full-year. Product revenue decreased 21% year-over-year. The chiller revenue remained constant, while the cogeneration revenue decreased due to the decreased demand and as Abinand noted in an earlier observation, this is – the cogeneration market is being impacted by the anti-gas sentiment. Product mix continues to vary year-to-year, but we expect to see demand for both cogeneration and chiller products going forward to improve. Our products gross margin decreased slightly to 33% – 33.1% in fiscal 2023, which compares to 33.5% in fiscal year 2022. Excluding the inventory provision recorded in 2023, our products gross margin would have been 36.7%, which is a slight improvement over the prior year.
Services revenue increased 20.4% year-over-year, which is due to the acquired maintenance contract and we also saw a 4.8% increase in existing contract revenue. For the full-year 2023, gross margin decreased to 45.5% compared to 54.2% in 2022 and this is due to increased services, labor and maturity costs incurred to address the engine replacements and due also to the provision that was recorded for obsolete inventory. I’ll now hand over the call to Abinand to review our 2024 plan.
Abinand Rangesh: Thank you, Roger. We have three phases to putting Tecogen on a pathway to financial health. The first is existing operations. Over the last year, we have increased our service revenue by assuming service contracts. We have also been working on establishing new sales channel relationships. When we look closely at our sales process, we discovered that most of our sales were made by convincing building owners about the efficiency benefits of our system. Traditionally, in HVAC industries, manufacturers’ reps sell to engineers who then specify equipment into projects. However, in our case, we need to ally ourselves with project developers in key markets such as indoor agriculture that can make the economic benefit argument directly to building owners.
Over the last year, we established relationships with some key project developers, some of whom are already selling complementary technologies such as modular chiller plants. We are in the middle of pivoting from being dependent on the New York City multifamily market to a broader nationwide market. So far, this has increased the size of our sales pipeline and we are being specified on multiple larger projects. The second phase is to position us to take advantage of utility capacity constraints. As more renewable energy is added to the utility grid, many electrical utilities struggle to provide sufficient power during peak times. The added cost to upgrade electrical distribution systems, in many cases, is prohibitive. So utilities provide lucrative payments for curtailing power during peak times.
