Solar power has massive potential to benefit humanity – with a different focus

From the BOE REPORT

 Terry Etam

As we slide inexorably into the clutches of Soviet-style cultural narrative control and thought prevention courtesy of ‘fact-checking’ institutions and their oddly subjective ‘fact books’, I offer the following conundrum as a hurled wrench into the cogs of the greasy gears of the thought police:

Solar power could soon become a wonderful thing for humanity.

As a heretical writer on an oil/gas centric website – most likely soon to be flagged by governmental decree and definition a writhing pit of misinformation or disinformation (take your pick – bill C-11 & spawn won’t split hairs) –  yes, I offer a ringing endorsement for solar power.

Not as a blanket solution of course; I may be heretical but I’m not insane. And not as an olive branch to those that think solar can become some kind of backbone of the electrical system. The enthusiasm herein for solar is in reference to the technology as a potential building block for a whole other aspect of civilization that is more desperately needed by a factor of ten than the current collective spastic heave that is our war on carbon emissions.

Solar power may prove to be an excellent solution to one of the world’s most considerable problems: a lack of potable water.

Water desalination from the sun is not exactly new technology, it likely has been around longer than the world’s oldest profession. (Hard to pin that point in history exactly but hey it gives context that perks up the ears of most people. Suffice it to say that solar distillation has been around for thousands of years.)

My inbox, spanning email and social media (looking at you Twitter) seems to be filled with one of two things these days – some modern form of prostitution (aw, look who started following me…wait a minute, is it necessary to show everyone that…) or something to do with renewable energy as a solution to emissions. Both have mastered the art of PR, both make shocking claims, both promise a good time for next to nothing, and both are going to get you in trouble. 

However, out of that morass did actually appear some eye-catching information (not the porn – it might be an eyeful but it’s not information). A Saudi Arabian firm named Acwa Power is one of the many that peppers me with news releases, and one of them somehow stood out in the flow: Acwa Power announced the Hassyan sea water desalination plant that will use solar power to produce 180 million gallons of desalinated water, per day.

Big wild numbers are difficult to contextualize on their own, so here’s a visual: an Olympic sized swimming pool, 165 feet long and 56 feet wide, holds just under 500,000 US gallons. This Acwa Power project could fill 360 of them, every day.

Of even more significance is that the price of such desalination has been tumbling. In 1970, the cost for reverse osmosis desalinated water was about $5 per cubic meter. By 2005, the cost had fallen to about $1/m3. The Acwa Power project pegs the cost at $0.37. My recent City of Calgary water bill shows a water cost of $1.42/m3 which is about $1.03 US, or triple the price that Acwa is supplying water at.

Consider that falling cost structure along with Acwa’s total desalination capacity. The company can now produce 7.6 million cubic meters per day, or two billion gallons – enough to fill 4,000 Olympic size swimming pools, every day. 

This is pretty fantastic news for humanity. It’s true that vast solar fields aren’t exactly environmentally friendly, but given that many regions short of water have vast tracts of marginally useful land (fly over much of the southwestern US and look out the window, for example) that might be a fantastic home for solar power if the trade off is to fill a bunch of swimming pools every day, or, who knows, maybe even grow some vegetables or irrigate some trees.

Imagine if in future vast pipelines are built from coastal areas inland, carrying enough water for cities in desperate need, all at low cost. Maybe the pipelines bring sea water inland for desalination, where vast stretches of nearly empty land could be utilized for solar desalination.

Solar could be utilized exactly as it works best – by providing a service not tied to the persistent timing demands of customers. Other fuels couldn’t touch it, assuming Acwa’s economics are sound elsewhere.

Such is the path forward for the ‘energy transition’; that is how we are going to make actual progress in utilization of renewable energy. In fact, the term ‘energy transition’ should probably be junked, because it has become so loaded and politicized that it is like a rusted out junk-heap smoking down the freeway.

We aren’t really transitioning away from any particular form of energy; several centuries after coal appeared as a major industrial fuel, the world now continues to set annual consumption records for the stuff. Same as oil. Same as natural gas.

You don’t have to be serious student, only half-interested will suffice, in energy history to quickly grasp the reason for the rise of coal, and what that cheap/easy fuel allowed humans to accomplish; to quickly grasp the significance of oil, and what it allowed humans to do; to quickly grasp the significance of natural gas as some sort of miraculous heating fuel that allowed mass settlement in very cold regions, that allowed manufacture of countless things…and on and on. Maybe solar power has found its niche where it can be of vast benefit to humanity.

In a nutshell, that’s the story of energy – the obvious massive potential of new developments that move humanity forward not in tiny steps but in large strides. But those strides don’t come about by abolishing the existing systems, unless the new technology is so vitally advanced that it renders obsolete any demand for the previous. Notice the nuance there; a transition happens by a draw to the new, not an abolition of the existing. The adoption of automobiles didn’t require the execution of horses. 

Despite the airplay given to opponents in the media, there is no grand villainy in the energy world. The fact that every single person relies on hydrocarbons to the extent they do (which is fully and completely) is quite clearly the consequence of the utility of those fuels over time, not a nefarious scheme for world dominance by producers. In fact, if any technology could have supplanted large quantities of hydrocarbons, it would have been nuclear power – but many of the most fanatical anti-nuclear people are also anti-hydrocarbons (Greenpeace, for example), while I know very few oilpatch people that campaign against nuclear. 

Every single consumer would prefer to have cheaper, cleaner energy, but not at the expense of reliability. No threat is more instinctually horrifying than the thought of running out of fuel when we need it most. Elements of the WEF crowd are even acknowledging this; Bill Gates recently pointed out that “If you try to do climate brute force, you will get people who say, ‘I like climate but I don’t want to bear that cost and reduce my standard of living.’ “ And that’s here in the west; in the developing world, the conversation is far more abrupt than that. 

Any ‘energy transition’ has to be built around those cold hard realities. Governments need to stop trying to quash certain industries just because they’ve been led to believe that doing so is the path forward. It isn’t.

You might wonder whether this animosity towards hydrocarbons is more imagined than real. Consider this: Covering Climate Now is an affiliation of over 500 news outlets, organizations, professional howlers, and every group of rag-tag semi-employable grad students that has come together under the climate banner. The organization includes such media pillars as Reuters and Newsweek.

On their Projects page is a project called: Climate crimes – investigating “big oil’s complicity in the climate crisis and attempts to hold the fossil fuel industry accountable.”

Hmm. Ignoring the incredible mental deficiencies and dexterities required to refrain from cataloguing the benefits brought to humanity by hydrocarbons (that is, almost all of them), one has to wonder why they aren’t going after “Big Coal”. Is it because the developing world would, if in a good mood, throw them out on their ear?

We remain silent on this bullsh*t at our peril. Not just as an industry – the antics of these clowns will only make reserves more valuable when demand is obviously so high – but as humanity. It is the less well off, the non-Tesla drivers, that will take it on the chin when our existing hydrocarbon supply chain is pummeled into oblivion.

Please contrast their witch hunt with the fact that there is no issue with speaking on an oil and gas-centric website of the benefits of solar (and hydrogen, and nuclear, etc.) because those things aren’t the competition most make it out to be. Seven billion people are striving to live like the other billion, and the foundation upon which they will make progress is affordable, reliable energy.

Add in the west’s newfound fascination with AI, and data centers, and air conditioners, among many other power-sucking accoutrements, and it is clear that we need all forms of energy, in as much quantity as we can provide.

It is safe to take this idea one step further. Consider that the oil patch has a waste water problem; many oilfields have high water cuts, and that impure water incurs costs to transport and dispose. What if solar power could be harnessed to distill much of that waste water – the process could provide very valuable new potable water sources in the parched prairies, could lower transportation and disposal costs of waste water, and could reduce emissions associated with transportation, processing and disposal of all that waste water.

I would bet that the oil patch would wholeheartedly embrace the concept of utilizing solar energy long before the Guilbeaults of the world could embrace the value of natural gas and harness it to full potential.

It should be up to the wisdom of our leaders to remember the miracles of the division of labour, and apply it to energy. Not everyone in a village should be a boot maker; not every country should try to be master of all industries; and some forms of energy will work wonders in one area but not in another. Solar power is a decent supplement to a power grid, up to a very limited point, but might be a game-changer in the field of desalination. Find the best use for each niche. EVs might be fantastic city delivery vehicles/cabs/etc. but might never work in the cold rural heartland. So what? It’s not an issue at all, except that governments are having a phenomenally difficult time accepting the reality that blanket climate initiatives are doomed to fail, in a very painful way.

Sooner or later we will start coming to our senses policy-wise, but there are going to have to be some wake-up calls along the way before we get there. 

Energy conversations should be positive and, most of all, grounded in reality. Life depends on it. Find out more in  “The End of Fossil Fuel Insanity” at Amazon.ca, Indigo.ca, or Amazon.com. Thanks!

Read more insightful analysis from Terry Etam here, or email Terry here.

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Addendum from Charles.

Wind Power is also a potentially excellent means to operate a desalination plant, especially when one avoids electrical generation altogether with: Direct-Driven Wind Powered Desalination: Mechanical-Hydraulic Systems

From: Integration of Wind Energy and Desalination Systems: A Review Study

6. Direct-Driven Wind Powered Desalination: Mechanical-Hydraulic Systems

All the systems presented before consider electricity as the intermediate energy medium: the mechanical energy of a turbine is converted into electrical energy, which is then used to power the equipment needed for the desalination process. To reduce the intermediate energy losses, the electrical conversion step can be avoided. This is the case of stand-alone systems where the wind turbine is mechanically and hydraulically connected to the RO system.

This means that the generator and the electronic components are eliminated. In their place, the rotor is mechanically connected to the shaft of the pump or compressor that drive the desalination process. The pump and compressor can be placed at the bottom of the tower or at the ground level, so that a system of gearboxes, pistons and belt transmission system is used for transmitting the motion [77,78,79,80]. Another possibility is to locate the compressor and the pump directly in the nacelle [81,82,83]. In these cases, the fluid is pressurised directly there, and act as a energy transfer medium. A description of several type of rotor-pump connections in wind turbines with hydraulic transmission system was presented in Chen et al. [84].

The use of a mechanic/hydraulic transmission system bring several advantages. In particular, good performances, robustness and reliability, that are particularly attractive for remote area applications [77,85,86]. In addition, the elimination on the generator leads to a noticeable reduction of weight in the nacelle. An overview of the prototype and conceptual design of wind-driven desalination systems with mechanic and hydraulic connection is presented in the following subsection, and summarised in Table 5.

Table 5. Stand alone with direct mechanic–hydraulic connection.

6.1. With Intermediate Energy Storage

One of the first prototypes of directly connected wind-driven desalination systems was developed and tested for groundwater desalination in 1988 [77]. There, an Aermotor fan-blade windmill extracted water from a well. In such a wind pump, the rotational motion of the rotor is converted by a geared mechanism to an up and down motion, that drives a pump rod inside the well.

In this way, water was pumped up the pipe at each upstroke and was delivered to pressure tanks at a pressure of 600–1100 kPa. The pressure vessels had the role of hydraulic accumulator, as energy storage. A solenoid valve allowed the flow of pressurised water from the pressure vessels to the membranes for the desalination process when a pre-set pressure level was reached. A simple schematic of the system is presented in Figure 5.

Figure 5. Schematics of the pilot project described in [77].

The prototype was operational for 13 months, and the data collected during operations proved the effectiveness of such a system, even though the pressure losses of the system amounted up to 52%, and the recovery rate achieved values of 9–9.7%: that was very close to the target value of 10%, but still lower than conventional desalination systems.

The plant resulted to be economically feasible if compared with conventional water production technologies when the capacity is 500 L/d or more, but not convenient when water carting is possible at a distance below 30–40 km. To increase the efficiency and reduce the energy losses associated with the brine stream (over 90% at 10% recovery rate), the use of an energy recovery device was suggested. Furthermore, a self regulation and system control is absolutely needed, and a diesel generator or gasoline pump is necessary to cover for always guaranteeing potable water.

A similar prototype was built and tested in Coconut Island, Hawaii [78], see Figure 6. Again, a multivane wind pump was used to pressurised brackish water, that was stored in a hydro pneumatic flow-pressure stabiliser. However, in this case not one but a series of solenoid valves are used to regulate the flow to the desalination unit, opening and closing sequentially in correspondence of different pressure levels reached in the hydro-pneumatic storage. In this way, the operating water pressure is kept approximately constant, regardless of the wind speeds.

Figure 6. Schematics of the pilot project described in [78].

In the execution of the project [79], the ability to create different pressure levels was used for including water pre-treatment in the system. In the first stage of operation, the water pressure was pretreated. In the second stage, the pretreated water was pressurised further for RO desalination. Furthermore, a modification of the prototype was implemented to let the system work also at different feed water salinities: several RO unit as put in parallel, each one able to work for a specific range of feed water salinity.

The control system measured the concentration of the feed water and then sends the pretreated water to the corresponding reverse osmosis pressure vessel. The prototype was then successfully managing varying wind speed and feed water concentrations. However, both cases discussed above are only suitable for brackish water desalination, since the wind pump system is not able to rise the pressure to the level required for seawater desalination.

A pressure accumulator was presented in WindDeSalter technology [82]. In WindDeSalter technology, the desalination plant is directly connected to the wind turbine, and completely integrated within the wind turbine tower. Two different configurations are possible, either integration with RO desalination or with MVC, as shown in Figure 7. In both cases, seawater is pre-filtrated and stored in a built-in tank on the bottom of the tower. From there, the prefiltrated seawater is pumped up for being desalinated.

Figure 7. Schematics of the pilot project described in [82]: on the left, the version with reverse osmosis as desalination technology; on the right, the one with mechanical vapour compression.

In the case of RO desalination, water is pumped up to the nacelle, where pumps connected to the rotor via a gearbox pressurise it and send it to the pressure accumulator and to the RO units, located on the tower just below the nacelle. The pressure accumulator smoothen the pressure fluctuations and the peak loads, while a control device regulate the pressurised volume flow of sea water via a flow control valve, and the power produced by the wind turbine via the blade pitch mechanism. Furthermore, several pumps and RO desalination unit can be activated or deactivated depending on the available wind power.

In the case of MVC desalination, the pre-filtrated seawater is first pre-heated, and then it is pumped to the evapourator/condenser located in the top of the tower. In this case, the compressor of the MVC system is directly connected to the rotor of the wind turbine. Then, the freshwater and the brine produced are handled as in the RO desalination configuration. The authors concluded that such a system is feasible and cost competitive compared with conventional technologies.

An innovative hydro-pneumatic energy storage system was integrated in a floating offshore wind-driven seawater desalination system in Cutajar et al. [81], in Figure 8. In this case study, a floating offshore wind turbine supported by a tension leg platform is directly used for pressurising seawater. The rotational motion of the rotor is converted in linear motion by a swash plate piston pump, replacing the generator in the nacelle.

Figure 8. Schematics of the pilot project described in [81].

The pressurised seawater is then accumulated into the submersed chamber, located into the gravity foundation of the tension leg platforms and anchored to the seabed, of a two chamber hydro-pneumatic storage. The air with which both chambers are pre-filled is then pushed trough the umbilical into the other, floating chamber and compressed. This way the system is charging and the energy is stored. When there is not enough wind, instead, the air in the floating chamber is allowed to expand, pushing seawater out at high pressure.

The pressurised seawater is then directed to the reverse osmosis module, located on the platform, and is desalinated. The freshwater obtained can be pumped to the shore by a booster pump, while the brine is recirculated in a PX ERD exchanger. The residual energy in the brine is transmitted to part of the pre-treated water that is stored in the liquid piston chamber, while the exhausted brine is discharged into the open sea.

The paper provides a mathematical and computational model to simulate the system and analyse two flow control schemes. The first one acts to maintain a constant pressure to the feed flow to the RO membranes, while the second one aims at maintaining a constant flow rate. Both schemes prevent the emptying or the overfilling of the lower chamber. Results from the simulation show that the proposed configuration and control schemes provide a good smoothing of the fluctuations, being able to produce 33,000 m33/d with a 5 MW wind turbine and 6.5 MWh hydro-penumatic storage.

6.2. Without Energy Storage but Direct Connection

However, energy storage systems increase the initial cost and the weight and volume of the wind-driven desalination plant. There is no energy storage in the small prototype described by Heijman et al. [80], in Figure 9. The rotor of the multivane wind turbine is directly connected to the shaft of the high pressure pump of the SWRO desalination unit at ground level, by means of a bevel gear, a vertical shaft and a belt drive.

Figure 9. Schematics of the pilot project described in [80].

The motor of the energy recovery device is mounted on the same shaft of the high pressure pump, therefore they always have the same rotational speed. Due to the direct mechanical connection of the wind turbine and the pump and the absence of any intermediate storage device, the pump speed, and so the permeate production, varies with wind. In this way, the recovery rate can be maintained fixed without the need of any extra regulators ad controls. Dealing with variable process conditions, the prototype was able to achieve a maximum recovery of 25% (compared with 40–50% of typical value for seawater desalination in commercial systems) and a variable permeate flow. The system includes a tank for storing freshwater to cover for the period of wind unavailability.

The high pressure pump replacing the generator is located in the nacelle and directly connected to the wind turbine rotor in the prototype described in Greco et al. [83], see Figure 10. Pre-filtrated seawater is pressurised in the nacelle and delivered partly to a SWRO desalination module for freshwater production and partly to a Pelton turbine generator for electricity production.

Figure 10. Schematics of the pilot project described in [83].

An isobaric energy recovery device (iSave) is used to recover energy from the brine, pressurising part of the seawater. This portion of seawater is then deducted from the water that is processed by the high pressure pump. The prototype, that is mainly composed of on-shelf components, is designed for a rated desalination capacity of 600 m33/d of produced water. Given the direct connection between the wind turbine rotor and of the high pressure pump, the flow rate and the pressure of the stream provided by the latter vary depending on the wind speed.

Therefore, an operational strategy is proposed to let the system operate within the limits imposed by each component, maximising freshwater and electricity production. The operational strategy is based on the active control of the collective blade-pitch mechanism, on the opening position of the spear valve of the Pelton turbine, and on the flow rates handled by the ERD.

Finally, a new concept of floating wind turbine, the Wind Energy Marine Unit WEMU, is employed for desalinating seawater in [87,88]. A WEMU is a wind turbine with vertical axis, around which rotates a semi-subermgible rotating pontoon, as a sort of vertical blades structure. A WEMU is provided of a a hydraulic transmission system, consisting of hydrostatic water pumps directly connected to the rotor, and high head water turbines for the production of electricity.

For its application for seawater desalination, two different configurations are proposed, as represented in Figure 11. In [87], the WEMU is used for Multi Stage Flash distillation (MSF) desalination. The water pumped by the hydraulic transmission system of the WEMU is partly used for electricity production via a hydraulic head turbine generator. The electricity generated is used for heating the remaining pressurised seawater, which is than distilled in the MSF plant.

Figure 11. Schematics of the pilot project described in [87] (on the left) and on [88], on the right.

Heat can be recycled from the brine and the permeate by pre-heating the feed seawater through heat exchangers. In [88], instead, the water pressurised by the hydraulic transmission system is directed to an RO module and desalinated. The permeate is then set to the shore. Even in this case energy is recovered, by processing the high pressure brine through a high-head hydraulic turbine generator, producing electricity. According to the authors such a system is the most promising for partially solving the water lack problem in Northern Crimea, with the additional advantage of providing also electrical energy.

While the conventional electrical drive transmission system is well diffused and predominant for wind turbines, the use of hydraulic or mechanical drive transmission systems in wind energy is still in the development phase and covers a niche market. The lower diffusion is therefore reflected in the limited number of prototypes and studies on directly connected wind drive desalination systems. The few pilot tested or proposed have a wide range of wind power capacity (from below 1 kW to 8 MW) and water production capacity (from below 1 m33/d up to 864,000 m33/d), have different layout configurations and wind turbine shapes.

However, there is a clear predominance of the reverse osmosis as desalination technology. It is also interesting to notice that the majorities of the most recent prototypes or case studies are intended for offshore applications, rather than onshore. From the tests and simulations presented it is seen that there are several operational strategy that can be adopted to successfully cope with the fluctuations of wind energy and, once the technologies will develop further, the results may be promising and competitive with respect to conventional systems.