Autonomous Photovoltaic Optimizations with Liquids OPALE

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Autonomous Photovoltaic Optimizations with Liquids OPALE




by Remundo » 03/09/11, 14:35

Hello to all Econologues,

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I open this topic to introduce our 2 prototypes OPALE,

optimizations
photovoltaic
Autonomous with
Liquids in
Flow


La OPALE photovoltaic barn
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and OPALE Photovoltaic Dairy
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OPALE is a technology developed by Sycomoreen that improves the photovoltaic production of an installation between 5 and 20% in metropolitan France.

Another OPALE option is to produce hot water from a pre-existing photovoltaic field.

We are looking for partners to develop this invention.

Find more information and projects related to renewable energies on the Sycomoreen website, as well as Sycamoree FAQ on photovoltaic issues.

See you soon.

Remundo for SYCOMOREEN
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by Remundo » 03/09/11, 14:38

The invention (OPAL) relates to a multi-tank device(REP, REC, RLS) comprising at least one pump (PMP), integrated return filtering (FRI) to at least one of the tanks, integrated flow filtering (FDI) at each pump (PMP), ascending pipes ( ASC, ASC1, ASC2) and ramps (RA, RA1, RA2, RA3) watering, managed by a seasonal control with thermostatic triggers (TST), photosensitive (PHO) and temporal (RHP, RTE) realizing with flowing liquids such as rainwater (EP), preheated rainwater (EC) or specific liquids (LS) all the necessary optimizations in the operation of a field of photovoltaic panels (CPV) on roof or on the ground, orientable or not, to know :

1. Cooling panels (except winter)

2. Snow removal / defrosting of the panels (winter)

3. Panel cleaning (all season)
at. Organic deposits
b. Inorganic deposits

4. The attenuation of the optical index jump between the air and the glass of the panels (any season)

5. Thermal energy extraction (all season)

The present invention (OPALE) is thus characterized by the following elements and functions:

1. The use of different liquids stored in:
at. at least one tank (REP) of rainwater (EP),
b. at least one reservoir (RLS) of specific liquid (LS) which will be in particular an antifreeze (for example water / alcohol) or an aqueous acid solution, or a reservoir (REC) of heated water (EC), or any specific liquid ( LS) considered appropriate,

2. At least one pump (PMP) whose suction (ASP) is immersed, possibly by means of valves (VDP, VDC, VDS):
at. In a rainwater tank (REP) for the summer period,
b. In the antifreeze tank (RLS) or alternatively in the tank (REC) of heated water (EC) for the winter period,
c. In a tank (RLS) of specific liquid (LS) during exceptional interventions of intense cleaning (with acidic water or organic diluent).

3. Integrated dual filtering (FRI, FDI):
at. The integrated return fluid (FRI) filtering on at least one of the tanks (REP, RLS, REC) consisting of at least one reusable cleaning filter-treated dual-stage box (BBE) with a removable cover (CAM), a support grid (GRI) held by screws (VI1, VI2, VI3, VI4), with a distribution member (DIS) towards the liquid reservoir (REP, RLS, REC),
b. The filtering of the integrated suction liquid (FDI) at the suction (ASP) consisting of a reusable filter head or surface (TFI, SFI) after cleaning,

4. An optional heating integrated in at least one tank (REP, RLS) comprising either a coil (SER) where the domestic hot water (DHW) flows, a heating resistor (RCH) or both (SER, RCH) ,

5. Sensors and triggers for the pump and / or heating resistor (RCH):
at. Thermosensitive: a thermostatic relay (TST)
b. Photosensitive: a twilight relay (PHO)
c. Time-sensitive: a programmable time relay (RHP) and an electrical time relay (RTE),

6. Ascending pipes (ASC, ASC1, ASC2) bringing the chosen fluid to the top of the photovoltaic field (CPV),

7. At least one irrigation boom (RA, RA1, RA2, RA3) from which the fluid flows,

8. An optional removable greenhouse (SAM) covering the photovoltaic field (CPV) according to the season,
9. Gutters (CHN) collecting the fluid,

10. A removable flow plane (PEA) which deportes or not the flowing fluids outside the gutters (CHN)

11. Return lines (RET) to the tanks (REP, RLS, REC).

12. At least one float (FLO), at least one distributor (DIS) and at least one overflow evacuation (TRP) for managing the fluid level in the tanks (REP, REC, RLS)
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by Remundo » 03/09/11, 14:40

Typical implementation of OPALE elements on a photovoltaic roof

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by Remundo » 03/09/11, 14:42

The presentation of the present device of Autonomous Photovoltaic Optimizations with Flow Liquids (OPALE) will be based on 9 technical figures (Fig. 1 / 32 in Fig. 9 / 32) and 23 figures of scientific resources (Fig. 10 / 32 to Fig. 32 / 32) appended to this document which will be organized according to the following plan:

1. The existing photovoltaic improvements:
at. Cooling panels
b. Snow removal of the panels
c. Cleaning the panels
d. filtering
e. Anti-reflective surface
f. Thermal extraction


2. Summary of the state of the art and contribution of OPALE
at. For cooling panels
b. For the snow removal of the panels
c. For cleaning panels
d. For filtering
e. For anti-reflective surfaces
f. For thermal extraction


3. Autonomous Photovoltaic Optimizations with Flowing Liquids (OPALE):
at. Components of the OPALE system
b. Cooling (except winter)
i. Hydraulic dimensioning
ii. Piloting the triggering of pumping
c. Snow removal / defrosting of the panels (winter)
d. Integrated filtering and heating
e. Panel cleaning (all season)
f. Attenuation of optical / air optical index jump
g. Thermal energy extraction (all season)
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by Remundo » 03/09/11, 14:44

Typical implementation of OPALE elements on a motorized photovoltaic mast in a solar tracker
(solar tracking)

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by Remundo » 03/09/11, 14:51

1. Existing photovoltaic upgrades

1a) The cooling of the photovoltaic panels is an important issue because the power of a panel typically decreases from 0,35% to 0.5% per ° C above 20 ° C, as shown in Figures 10 and 11.

The solar statistics estimate that in France, an installation with panels integrated in the roof loses 5 15% of its annual production because of their heating, and up to 35% of its instantaneous power on hot and sunny days.

Thus several panel cooling devices have been proposed, most often with liquid water. Thus we find:

- examples of photovoltaic modules with integrated cooling in the panel in DE2020060160108U1 by SUNZENIT Gmbh or in FR2566183A1 by Roger LUCCIONI or also FR2911997A1 by Guy DIEMUNSCH, also a liquid completely surrounding the cells as in WO0036618A1 by Stichting Energieonderzoek Centrum Nederland,
- examples of cooling with runoff of liquid on the roof (often closed circuit and recovery of rainwater) in SI22844A / WO2010005402A3 by Kajetan BAJT or JP62013084A by Katsumi KAWASHIMA which are considered as a state of the art close to the present invention,
- examples refrigerating and / or heat pump installations as in JP2006183933A by Masahisa OTAKE or EP2093808A2 by Alfonso DI DONATO,
- examples of photovoltaic and thermal hybrid panels (PVT) with various variants, especially in CN201365210 by JUNJIE / DANDAN, CN201368606Y by WU / GOU, JP2003199377 by KOMAI / YOSHIKA, or K100622949B1 by KIM JONG / KIM TAE, or WO2009111017A3 by Edwin COX. It is sometimes proposed to concentrate the radiation as in US6630622B2 by Annemarie HVISTENDAHL KONOLD or WO0008690A2 by Windbaum Forschungs und Entwicklungs Gmbh. For information, figures 10 and 11 are derived from performance publications by Holtkamp SES on its hybrid photovoltaic / thermal glass panels

1b) Snow removal / deicing of photovoltaic panels is a theme that is less often discussed; however, it is of particular importance in mountainous or snow-covered areas: to benefit from the strong albedo of the snow and to have a good production, it is necessary to drive snow or frost fallen on the photovoltaic installation. In this case, the problem of cooling is obsolete and replaced by a problem of snow removal and several methods have been proposed for this purpose:

- examples of electric heating elements to melt ice, additional as in CN201340855, or integrated in panels by reverse current as in DE102006004712A1 by Inek Solar AG or JP9023019 or JP62179776 by KYOCERA, or KR20100005291A by YU HEUNG SOO
- examples of hot-air cast iron as in DE102006054114A1 by Gertraud HÖCHSTETTER or by CO2 current as in JP2006029668 by OTAKE / MURATA,
- examples of water runoff melting as in JP2003056135 by Hitoshi HORIKAWA or JP2005155272 by OE / TANIKOSHI, or WO2009139586 by Soo YU HEUNG
- examples of mechanical snow removal as in DE10013989A1 by René NEUMANN or CN201338000Y by DAJIAN / HONGSHENG, or DE202005012844U1 by STEIBLE / ALBRECHT

1 C) The cleaning of photovoltaic panels is also proposed according to different methods:

- self-cleaning surface module as in CN201181709Y by Liu JINWEI, or self-cleaning physicochemical films to be applied posteriorly on the panels,
- use of mechanical means (brushing, wiping ...) as in DE10013989A1 by René NEUMANN or KR20090090722A by JUNG HAE / KIM GYEONG or WO2008014760A2 by Gerd HETTINGER,
- combination of coolant runoff and cleaning as in KR20090071895A by Jae LEE CHAN or WO2009139586 by Soo YU HEUNG.

1d) Filtering is applied to applications where the runoff of the liquid is directly in the open air. In practice, it is often proposed a closed water circuit with tank to not run to "lost water" while collecting rainwater.

However, roofs collect a lot of organic waste (bird droppings, insects, plant residues (leaves, twigs, dust) and minerals (dust from stone or sand, pollution brought by the wind and / or rain). leads to a very rapid fouling of the tanks and seriously compromises the operation of the pump and the irrigation ramp ensuring the runoff of the liquid on the photovoltaic field Very few patents on the subject of OPALE technically address this issue of filtering; JP62013084A can be cited, however, which recommends compartmentalizing the rainwater reservoir into a storage space and another one of decantation, but without filtering the fluid, or SI22844A which signals a simple return filtering of the loaded water. Departure filtering is not proposed.

1.e) The anti-reflection surfaces are developed most often by the deposition of thin layers on the glass surface of the photovoltaic panel so as to channel the maximum radiation to the photosensitive cells. Nevertheless, there remains a significant difference in optical indices between the air (n = 1) and the protective glass (n = 1.5) which causes the partial reflection of the radiation and therefore a weakened photovoltaic effect on the cells.

1.f) Thermal extraction for photovoltaic panels is possible.

As shown qualitatively in Figure 15, the imperfections of the photovoltaic effect and the very dark photosensitive materials lead to a degradation of about 80% of the radiation in heat. The temperature of the panel always increases until the thermal power lost by the panel (by conducto-convection and infrared re-emission) is equal to the thermal power received.

Without forced cooling, the equilibrium temperature is in the vicinity of 90 ° C when the atmosphere is hot with intense radiation, and typically 50 at 70 ° C - resulting in a decrease of about 30% for electrical power - .

Urban artist these high amplitude temperature cycles age the photosensitive elements through a slow decline in electrical efficiency (from 10 to 20% over a period of 20 years compared to the initial performances). This prejudicial heating phenomenon is sometimes enhanced by combining the techniques of solar thermal panels (circulating liquid under glass) with that of photovoltaic solar panels (constituting the hot absorbing surface). But the intense cooling of the panels and the obtaining of very hot water are incompatible. Only a compromise between the two is possible, with seasonal needs.
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by Remundo » 03/09/11, 14:52

OPALE integration on modular solar power plant with centralized management

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by Remundo » 03/09/11, 15:01

2. Summary of the state of the art and contributions from OPALE

Despite numerous proposals, each has more or less deep gaps:

2.a) for cooling panels

Integrated cooling solutions in the panel do not clean the outer wall exposed to soiling.

The solution of liquid runoff outside the panel is the most relevant, but with the addition of filtering solutions and fight against winter cold performance.

Finally, hybrid panels PVT do not insure their external cleaning and tend to overheat : in summer, decrease the production of hot water and favor photovoltaic production, in winter, do the opposite.

2.b) for snow removal / deicing of panels

The electric heating elements in the panel lead to additional cost and energy expenditure during their implementation. The same is true for the polarization / reverse current techniques of photovoltaic cells that require a very reliable control electronics.

The flow of hot air, necessarily energy-consuming, also requires specific panels and therefore expensive compared to a standard panel.

Mechanical snow removal requires quite complex and expensive brushing / wiping kinematics, especially for their maintenance, which, with sandy residues tend to scratch the glass of the panels.

the trickle technique is interesting because sloping, very little fluid and energy is enough to destabilize a layer of snow deposited on glass, provided to secure and automate the flow of fluid.

2.c) for cleaning panels

Self-cleaning films are generally chemically complex and their action is not sustainable or even ineffective because some soiling is particularly adherent, such as animal droppings or mineral deposits..

The rain is not always sufficient, or can itself be the cause of fouling when it carries natural dust like sand or artificial linked to industrial residues.

Brushing requires expensive mechanical architectures and can damage the panels, for example with the rubbing of residual sand on the glass.

In reality, only the runoff appears valid, but the simple runoff of water proves to be insufficient: it requires an effective filtering and specific liquids, with a controlled hydraulics.

2.d) for filtering

The state of the art shows great weaknesses in this area: it is ignored very often, sometimes reported, and often technically inadequate. The quantities of dirt collected by a roof are very important and must absolutely prevent them from entering the liquid tankswhether it is water or specific liquids.

OPALE filtering is strict both at the return and at the beginning of the fluid in order to keep the tanks clean as well as the strategic piping of the fluid, such as the aspiration (ASP) of the pump (PMP), the possible ascending pipes (ASC) or irrigation booms (RA, RA1, RA2, RA3) . However, this filtering is easy maintenance and cheap, without causing excessive hydraulic head losses.

2.e) for anti-reflective surfaces

The problem of reflection during the passage of light through the interface of 2 different optical indices is a known situation, sometimes sought or combated.

Photovoltaic panels create a transmission between an index of about 1 (that of the air) and an index of about 1,5 (that of the protective glass). Calculations of wave optics developed later show that this induces a reflection of about 4% in normal incidence, the situation deteriorating at 10% to an incidence of 50 ° (depending on the polarization of the wave) and up to at 100% when incidence becomes grazing.

This reflection is a net loss for photosensitive cells. The anti-reflection layer techniques exist, but are expensive and perishable because exposed to the aggressions suffered by the panels placed on the roof. In addition, they only work for a single wavelength.

Other considerations of wave optics indicate that a good compromise of anti-reflective layer index is the square root of the 2 indices to cross (see 3.f), in our case 1.225 . OPALE uses so suitable aqueous solutions because of 1,3 index about.

2.f) for thermal extraction

Thermal extraction systems often use the greenhouse effect thanks to an irremovable glass superimposed in front of the photovoltaic panel, which leads to its overheating even when there is no need for heating, especially in summer.

The photovoltaic efficiency then deteriorates considerably, unless it imposes a pumping energy consuming enough to evacuate the calories and provide a radiator to dissipate heat in the environment.

However, it is possible to store the heat in a large underground thermal buffer of the building, so as to draw heat during the winter. This type of installation is nevertheless expensive and very little used.

Finally, it is not possible to simultaneously obtain a maximum photovoltaic production and a hot return fluid. Photovoltaic and solar heating are incompatible in their need, but OPALE uses a removable greenhouse (SAM), mounted in winter and absent in summer.

Thus, as it will be developed, the OPALE system solves all the technical problems raised with simple and nevertheless automated means.

By the flow in closed circuit of large quantities of water with a controlled hydraulics, the device (OPALE) guarantees a maximum cooling, even in period of heat wave.

By combining this flow, with the daily need, with a multi-tank approach (EPIRB, REP, REC) rainwater (EP) or specific liquids (LS), the device (OPALE) ensures a regular cleaning and effective, which can be enhanced by the flow of specific liquids suitable for dissolving the most stubborn deposits on the photovoltaic field (CPV).

Thanks to the double integrated filtering (FRI, FDI) of the liquids on the return and the departure, with a two-stage box (BBE) with filtering surface (SFI) or with filtering head (TFI) implanted on the aspiration (ASP) of the pump (PMP), the device (OPALE) offers accessible filtering, effective and inexpensive to preserve dirt all tanks (REP, RLS, REC) and pipelines (ASP, PMP, ASC, ASC1, ASC2, RA, RA1, RA2, RA3) strategic.
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by Remundo » 03/09/11, 15:02

Two-stage filtering device for return fluids

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by Remundo » 03/09/11, 15:05

By multi-tank approach, either antifreeze (figs 12, 13 and 14), or heated water (EC), OPALE allows rapid snow removal with low energy consumption in winter..

Thanks to the flow of aqueous liquid, the device (OPALE) creates an anti-reflective layer for all wavelengths at no cost (figs 20 to 32).

The device (OPALE) allows a thermal extraction of the heat of the panels particularly adapted by the removable nature of the greenhouse (SAM) which will be put in place in winter and removed in the summer and the presence of a heated water tank (REC) that can communicate via a coil (SER) its heat with domestic hot water (DHW)

the combination of its thermostatic (TST), twilight (PHO), programmed time (RHP) and electrical time delay (RTE) relays, the device (OPALE) adapts intelligently to all situations in order to secure and rationalize the autonomous operation of the installation despite changing weather conditions.

Both for rooftop installations as shown in Figure 1, and for ground-based solar power plants as shown in the 2 (Modular OPALE) and 3 (Centralized OPALE) figures, a complete stand-alone system is available to guarantee all photovoltaic optimization despite seasonal and / or climatic variations:

1. Cooling panels (except winter),

2. Snow removal / defrosting of the panels (winter),

3. Panel cleaning (all seasons),

4. Fluid filtering

5. Attenuation of optical / air optical index jump (all seasons),

6. The thermal valorization of the heating of the photovoltaic panels (any season).


3. Autonomous Photovoltaic Optimizations
with Flowing Liquids (OPALE)


3.a) The components of the OPALE system

As shown in Figure 1 for roof installation, Figure 2 for stand-alone floor installation, or Figure 3 for a centrally managed floor installation, the device (OPALE) is installed on a photovoltaic field (CPV) and has at least 2 reservoirs of which:
- a tank (REP) of rainwater (EP)
- or a tank (RLS) of specific liquids (LS),
- or a tank (REC) of heated water (EC).

Specific liquids (LS) can be aqueous solutions:
* antifreeze:
- water / ethanol (as illustrated in figs.12 and 13)
- or salt (fig.14),
* organic diluent to carry organic deposits, * acid / base capable of dissolving inorganic deposits,
* heated water (EC) for either snow removal or hot water heating (DHW),
* or any other specific fluid deemed relevant.

The device (OPALE) also includes a pump (PMP) whose suction (ASP) plunges:
- in the rainwater tank (PWR) except in winter,
- in the antifreeze tank (RLS) in winter, or alternatively in the tank (REC) of heated water (EC),
- in the specific fluid reservoir (RLS) for thorough descaling and cleaning operations.
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