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Regenerating energy from pressure – We’re launching the Sea-Lix POPCO – a pressure control turbine for water distribution networks!

Water distribution networks around the globe are ignored by most of us – still we completely rely on their safe supply. Fresh water sources are threatened in many regions – in India, dependent on groundwater – nearly 55% of the wells have decreasing levels. It is predicet that 60% of their aquifers will be in critical condition before 2040! Its simply not enough water…

At the same time, the distribution networks are in a pretty pitiful state – they leak as sives! Some European countries have leakage rates of more than 70%. In a global perspective – one third of all waterworks have losses exceeding 40%. Several studies have concluded that reported leakage rates are often underreported – one should assume that realities are even worse.

In this mist, another fact arises – the water sector is one of the top global energy consumers. In the US, it consumes some 5% of all electricity generated. In the UK, this figure is “only” 3%… Irony or tragedy…..

Water distribution network assets are renewed at a frightfully slow paste – In Norway – at the rate of 0,7% per annum. That’s 7 meters of new pipe per kilometer per year! It will take some 145 years to come around the circle – thus, these networks will always be old! So, …. what other tools do we have in the box?

Data! …No, unfortunately not – data is practically speaking – not available. At least not to efficiently manage the proper operation of ageing water pipework. Sensor technology has come a long way, they are inexpensive and reliable but yet not widely in use in this sector. However, a number of suppliers are starting to introduce such products aimed at the water utility segment.

A little while back, we introduced the POGMO – a powerhouse for off-grid locations driven by Sea-Lix’ unique turbine technology – capable of powering a range of sensors and communicating data continuous – real time. This has been a bottleneck – as batteries are unfeasible, as is solar panels and windmills! Harvesting data will enable optimized pressure management of the networks. The potential of this is astonishing – a reduction of leakages ranging above 50% has been reported.

The next step for us has been to address practicalities concerning pressure management. Current state of the art relies on the use of Pressure Reduction Valves – PRV’s. These extract pressure, convert this to energy in the form of heat – which is lost as it disperses into the water. So, the performance of this is …100% ….loss. A parallel would be electrical cars without regenerative breaks. Thats not gonna happen – time to wake up!

The POPCO is a powerhouse and pressure control system. It extract energy represented by the surplus pressure required to be removed – dynamically, – dependent upon operational conditions in the network. Electricity generated may be consumed locally or sold on to the grid… or used to supply power to charging points for electric vehicles…

sea-lix_popco

Sea-Lix dual rotor turbine technology for power extraction and pressure control

Our platform technology, evolved from the tidal challenge, has proven to be extremely versatile and flexible and is now available for both hydrokinetic applications as well as for more conventional applications.

We have recently finalised the development of a unique “Power Off-Grid” turbine which has been designed to make use of a small pressure-loss to generate “on site” reliable and continuous power for monitoring and control equipment. This unit, the POGMO, has been welcomed by the water utilities sector in particular. Crucial data, and means of control required to properly manage water distribution networks, is sometimes not available simply because of lack of access to electrical power at hotspots in the water network. The POGMO can be integrated in the pipework and will allow the continuous powering of equipment such as pressure sensors, flowmeters, leakage detection equipment and even motors controlling valves, filters and others. The pressure loss generated by the POGMO is approximately 0.3 bar, maximum loss is limited to 0.5 bar.

This concept has been developed further to remove excess pressure – and (re)generate it to electrical power. Current practice in water distribution sectors is to manage excess pressure by the use of mechanical pressure reduction valves thereby creating waste heat. This approach is obviously not sustainable and is being jeopardized by an increasing number of stakeholders. Available continuous data harvested by sensors powered by the Sea-Lix’ POGMO will now also allow water utilities to regulate pressure and at the same time generate electricity by using our Pressure-to-Power (POPCO) turbine!

The illustration below presents the main features of the POGMO:

pogmo

Sea-Lix POGMO

 

The nature of the Sea-Lix concept allows an unusually compact design as the diameter of the rotors can be kept to a minimum. The two rotors are self-cancelling causing the downstream flow-pattern to be “homogeneous” thereby reducing potential erosion issues and allowing simpler mounting. We have utilized these two characteristics in our compact Plug n’ Play containerised hydropower station. The unit is truly self-contained, requiring only connection to water inlet and outlet.

The illustrations below presents Sea-Lix integrated hydropower unit. This particular application includes the pre-filtration of the water prior to entering the actual turbine. This is an add-on and is not a requirement for operations.

sea-lix_generator1sea-lix_generator2

Visit www.sea-lix.com if you want to learn more about us!

Sea-Lix; Hydropower – is still the most important renewable energy source. Sea-Lix introduces new clever and versatile turbine technology.

After spending more than a decade founding, developing, industrializing and commercializing our start-up babies; OceanSaver and MossHydro (among others) – time has come to nourish, nurse and realize our favorite baby – Sea-Lix!!

Back to 2007 – after chasing the beach at Plémont, Jersey – rather unsuccessfully – I decided to do it properly and read the tidal tables. As they say – timing is everything. And yes – I did find the beach… I also realized the vast potential of the tides….

This is a long time ago – even though, this moment represents the birth of what became Sea-Lix. On my return home, I sat down with Jason Dale (the other founder of Sea-Lix) to discuss the potentials of harvesting from the tides. Maybe somewhat naïve of even cocky (or both) – after looking at the various projects ongoing or being proposed at the time, we decided we could do better!

In light of a very busy schedule elsewise, the project sadly did not achieve the attention it deserved until 2011 when we filed two patent applications and established the project as a formal legal entity; the company Sea-Lix. From then, focus has been on developing the technology, identifying opportune markets and creating solutions for targeted applications.

So.., in 2016 – we were granted funds from Innovation Norway to establish a tidal/ free flow demonstrator at Vargfjorden in northern Norway – later the same year we decided to also develop a pressure control turbine, so keeping busy.

In between all this – we have finally had some spare time to develop our web identity. Please visit www.sea-lix.com when convenient, and we’ll tell you more!

Should you accept stainless steel filter-screens in your Ballast Water Management System?

By InBallast AS

About us: InBallast is an independent consultancy/ engineering company that delivers services related to ballast water management to ship-owners, vendors and regulators. Visit http://www.inballast.com to learn more about us.

Filters are the Achilles heel of any Ballast Water Management System that applies conventional water treatment technologies – thus, most ballast water management treatment efforts will be at risk of failing unless the filters are up for the task. This article highlights the importance of proper pre-filtration and the necessity to address and to understand filter issues in light of operational limitations and maintenance requirements.

Never better than the weakest link!

Simplistically, the ballast water discharge standard differentiate the target organisms in three size categories; >50um sized organisms (predominately zooplankton), 10-50um sized organisms (predominately algae) and lastly that of bacteria.

Most suppliers choose filtration with a cut-point at around 40 um resulting in an immediate and very efficient removal of zooplankton. For oxidation systems, this will (theoretically) lower the oxidant consumption and further enable compliance with very low or now requirements related to holding time. For UV systems – there are two vectors calling for introducing high efficiency filtration; a) the ability to ensure complete irradiation exposure (removing shades), and b) as zooplankton tend to be more resilient to UV- irradiation, exposure-time is a factor of importance. By eliminating a significant portion of zooplankton, inadequate and prolonged exposure is avoided. Some UV suppliers choose even smaller cut-point to improve over-all performance.

If the filter fails – you’re in trouble!

Filters in BWM applications fail for a number of reasons. Some filter technologies are simply not suited for the challenge – organic matter behave differently from inorganic matter and consequently require a different approach. Zooplankton respond differently from phytoplankton during filtration – there are also differences between freshwater and saline water biomass-response when being filtered.

Over the years, BWMS suppliers have reviewed and tested a number of different filtration concepts. In the early days, standard industrial filters were applied. Nowadays, most suppliers have developed special filters for ballast water filtration and newcomers have entered the market – offering specialised ballast water filters only. Single unit filters have grown in size and are now available matching the ballast water flowrates of very large vessels.

The products in the market today represents a substantial improvement compared with their precursors. However, the complexity of the challenge; limitations in space, vessels in-motion signature, variations in water filterability, variations in pressure, operational requirements and not least the corrosive nature of seawater synergised, unfortunately, by the often-elevated temperatures experienced in many areas of the world and not least in engine-rooms were most ballast water filters are installed – require compromise! We can see this in the different filter designs currently in use. It becomes however, somewhat ironic that still, the most used filter screen material is stainless steel, grade 316. As stated in the introduction in a recent report from one of the more reputable Class societies; Stainless steel is not suited for use in seawater applications. A stainless screen of the quality offered by most vendors will have a very short life unless treated with the utmost care. This include never being stored in saline water for any amount of time! How feasible is that?

Cheapskates, ignorance or couldn’t really be bothered if it works or not…!

So why is this the case? The most important component in the filter seems pretty much overlooked. Throughout the development in ballast water filtration as seen over the last decade or so, we would think that the imperative would have priority – namely that the filter screen material would ensure a practicable functional lifespan. We recently surveyed filters following only three months of operations. We had to take them off the vessel and have them replaced!

The argument for the choice relate of course to cost. Screens in higher quality materials are in use in many industries and are obviously available – they’re just more expensive (initially…) and have a more complex supply-chain. However, nothing that cannot be managed by some level of planning.

Experiences from BWMS’ type approval shipboard sea-trials, shows us that even the slightest contamination, caused by for example a leaking valve or remaining untreated water in the ballast tanks, may result in the ballast water discharge not meeting the ballast water discharge standard. This even goes for systems that treat on both intake and discharge.

Imagine a mere 0,1% valve leakage. A pump delivering 3000 m3/h to a 3000 m3 tank at an intake concentration of 100.000 individuals/m3 of > 50µm organisms will take 360 seconds or six minutes to exceed the IMO D-2 standard. The effect of a damaged filter will also cause a leakage – the consequence is pretty much the same – most likely incompliance!

Feasible solutions in sight?

But can a higher quality screen warrant an improved functional lifespan? And how can its function be assessed? The latter is easy – by sampling and analysis. In fact, the only way of gaining experience with BWMS’ efficiency in operation over time is by sampling and analysis. In order for this to happen simpler methods must be introduced – simple and reasonably accurate indicative methods are available. Regulators need to focus on introducing frameworks allowing these to be used – not for potential violation validation – but to gain knowledge. This is surely an issue to be debated by the IMO in light of the experience-building phase to be considered by MEPC 71. We fear there may not be much experience to gather unless mandatory performance monitoring programs are established. Maybe something similar to the VGP self-monitoring program could be considered?

Back to the screen quality! There are other impacts not assessed during system’s type approval – that of operational wear. Filters are certainly exposed to wear – both due to the debris load experienced during filtration but also as consequence of mechanical wear during backwash. There is good solid documentation available verifying that this will have a serious impact on functional lifespan. The available type approval protocols seem to have completely ignored this.

We took our concerns to InNano AS – a company specializing in smart materials engineering. InNano have developed surfaces applicable to various base materials including steels, stainless steel qualities, titanium, alumina and even some plastics – with some very different capabilities. InNano can provide photo-reactive surfaces, (super) hydrophobic/ hydrophilic surfaces, surfaces with extremely low surface tension, hard surfaces, dielectric surfaces and surfaces combining some of these different characteristics. So, we challenged them and had screens from different suppliers tested under so-called CASS conditions (Copper-Accelerated Acid Salt Spray). The tests used standard grade 316 stainless steel filter screens of the most frequently used sizes (25, 40 and 50 mm) and representing screens as used by different manufacturers. InNano modified the screens using 4 different surface preparation technologies. The reference-screens (as currently installed in ballast water filters) – all suffered corrosion after 6 to 24 hours. The test ran for some 350 hours – and yes, modified screens did survive the entire exposure without signs of corrosion.

So how much cheaper is it to choose a failing material! Well, if you cared about the result, would do chance it? If it affected you commercially, would you?

At the end of the day, it’s the customer who decide on quality! Ask your supplier of choice – how is the screen offered qualified in relation to operational wear and to corrosion? Are there any warranties? And what are the preconditions? The USCG fine for failing to meet the Ballast Water discharge standard is set at maximum US $35.000,00. That per violation per day.

…., so who’s saving!